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: An intake pipe downstream of a throttle valve is interconnected with an exhaust pipe via an EGR supply pipe and an EGR control valve is disposed in the EGR supply pipe. An engine load ratio (KLoff) in the engine steady operation with the EGR gas being not supplied, and another engine load ratio KLon in the engine steady operation with the EGR gas being supplied are expressed with respective linear functions of an intake pipe pressure (Pm) and stored in advance. The intake pipe pressure (Pm) is detected, KLoff and KLon are calculated from the detected intake pipe pressure (Pm) using the linear function expressions and, then, a difference between these values ?KL (=KLoff?KLon) is calculated. Based on the difference (?KL), the EGR control valve passing-through gas amount, which is an amount of the EGR gas passing through the EGR control valve, is calculated.

Abstract: A control system of an internal combustion engine provided with a throttle valve passage air flow calculation equation by which the throttle valve passage air flow mt is expressed as a function of the downstream side intake pipe pressure at the downstream side of the throttle valve and a cylinder intake air flow calculation equation by which the cylinder intake air flow mc is expressed as a function of the downstream side intake pipe pressure, where said downstream side intake pipe pressure Pm and cylinder intake air flow mc when the throttle valve passage air flow mt found from said throttle valve passage air flow calculation equation and the cylinder intake air flow mc found from said cylinder intake air flow calculation equation match are calculated as the downstream side intake pipe pressure Pmta and cylinder intake air flow mcta at the time of steady operation under the operating conditions at that time is provided.

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: An intake pipe downstream of a throttle valve is interconnected with an exhaust pipe via an EGR supply pipe and an EGR control valve is disposed in the EGR supply pipe. An engine load ratio (KLoff) in the engine steady operation with the EGR gas being not supplied, and another engine load ratio KLon in the engine steady operation with the EGR gas being supplied are expressed with respective linear functions of an intake pipe pressure (Pm) and stored in advance. The intake pipe pressure (Pm) is detected, KLoff and KLon are calculated from the detected intake pipe pressure (Pm) using the linear function expressions and, then, a difference between these values ?KL (=KLoff?KLon) is calculated. Based on the difference (?KL), the EGR control valve passing-through gas amount, which is an amount of the EGR gas passing through the EGR control valve, is calculated.

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: An apparatus and method for controlling the intake air amount in an internal combustion engine provided with a throttle valve and an intake air amount changing means linked with the same, the intake air amount control apparatus and method of an internal combustion engine finding a target intake air amount mcta based on an accelerator opening degree and engine speed (step 101), determining a target setting Cvta for said intake air amount changing means based on at least said target intake air amount (step 103), and finding a target throttle opening degree ?tta based on model equations creating a model of an engine intake system and expressing the air passing through the engine intake system from said target intake air amount mcta and the target setting Cvta (step 107).

Abstract: A cylinder inflow exhaust gas amount calculation system of an internal combustion engine provided with an intake passage, an exhaust passage, an exhaust gas recirculation passage connecting the intake passage and exhaust passage, and an exhaust gas flow rate control valve arranged in the exhaust gas recirculation passage for controlling the flow rate of the exhaust gas flowing in the exhaust gas recirculation passage, and the system calculating an amount of cylinder inflow exhaust gas defined as an amount of exhaust gas flowing into a cylinder, utilizing an amount of passage exhaust gas defined as an amount of exhaust gas passing through the exhaust gas flow rate control valve, wherein an amount of cylinder inflow exhaust gas is calculated considering the dead time corresponding to the time taken until the exhaust gas passing through the exhaust gas flow rate control valve reaches the cylinder and a tracking lag of a change in the amount of cylinder inflow exhaust gas with respect to a change in the amount of

Abstract: An intake passage upstream of a throttle valve is divided into a plurality of intake divided-flow conduits, and air flow meters are arranged in the respective intake divided-flow conduits. The throttle opening is obtained, and a throttle valve passing-through air amount, which is an amount of air passing through the throttle valve, is calculated on the basis of the throttle opening. Each air flow meter-detecting intake air amount, which is an intake air amount to be detected by the air flow meter, assuming that air flows through each intake divided-flow conduit by a part of the throttle valve passing-through air amount, the part being determined by a divided-flow ratio of the corresponding intake divided-flow conduit, is estimated, and a total value of the estimated air flow meter-detecting intake air amounts is then estimated. The engine is controlled on the basis of the total air flow meter-detecting intake air amount.

Abstract: In a device for estimating an amount of intake air of an internal combustion engine, wherein an amount of intake air passing through the throttle valve is calculated by using of an upstream side intake air pressure upstream of the throttle valve and a downstream side intake air pressure downstream of the throttle valve, and an amount of intake air supplied into the cylinder is estimated on the basis of the amount of intake air passing through the throttle valve, the upstream side intake air pressure used at the time when the amount of intake air passing through the throttle valve is calculated is detected or calculated to take account of a pressure loss, produced by at least an air-cleaner, from the atmospheric pressure.

Abstract: A control system of an internal combustion engine provided with a throttle valve passage air flow calculation equation by which the throttle valve passage air flow mt is expressed as a function of the downstream side intake pipe pressure at the downstream side of the throttle valve and a cylinder intake air flow calculation equation by which the cylinder intake air flow mc is expressed as a function of the downstream side intake pipe pressure, where said downstream side intake pipe pressure Pm and cylinder intake air flow mc when the throttle valve passage air flow mt found from said throttle valve passage air flow calculation equation and the cylinder intake air flow mc found from said cylinder intake air flow calculation equation match are calculated as the downstream side intake pipe pressure Pmta and cylinder intake air flow mcta at the time of steady operation under the operating conditions at that time is provided.

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: A target value of an engine load ratio is calculated. A target throttle opening required for making the actual engine load ratio equal to the target engine load ratio is calculated on the basis of an intake pipe pressure which is a pressure in the intake passage downstream of the throttle valve. A convergent throttle opening, which is a throttle opening to which the actual throttle opening converges assuming that the target intake air amount is kept at the calculated target intake air amount, is calculated. A final target throttle opening is set to the target throttle opening when the engine transient operation is in process, and to the convergent throttle opening when the engine steady operation is in process. Then, the throttle valve is driven so that the actual throttle opening is made equal to the final target throttle valve.

Abstract: A target value of an engine load ratio is calculated. A target throttle opening required for making the actual engine load ratio equal to the target engine load ratio is calculated on the basis of an intake pipe pressure which is a pressure in the intake passage downstream of the throttle valve. A convergent throttle opening, which is a throttle opening to which the actual throttle opening converges assuming that the target intake air amount is kept at the calculated target intake air amount, is calculated. A final target throttle opening is set to the target throttle opening when the engine transient operation is in process, and to the convergent throttle opening when the engine steady operation is in process. Then, the throttle valve is driven so that the actual throttle opening is made equal to the final target throttle valve.

Abstract: A target value of an engine load ratio is calculated. A target throttle opening required for making the actual engine load ratio equal to the target engine load ratio is calculated on the basis of an intake pipe pressure which is a pressure in the intake passage downstream of the throttle valve. It is judged whether the target throttle opening can be realized by a step motor. A final target throttle opening is set to a maximum or minimum throttle opening which can be realized by the step motor when it is judged that the calculated target throttle opening cannot be realized by the step motor. The step motor drives the throttle valve so that the actual throttle opening is made equal to the final target throttle opening, and the intake pipe pressure is estimated on the basis of the final target throttle opening.

Abstract: A target value of an engine load ratio is calculated. A target throttle opening required for making the actual engine load ratio equal to the target engine load ratio is calculated on the basis of an intake pipe pressure which is a pressure in the intake passage downstream of the throttle valve. It is judged whether the target throttle opening can be realized by a step motor. A final target throttle opening is set to a maximum or minimum throttle opening which can be realized by the step motor when it is judged that the calculated target throttle opening cannot be realized by the step motor. The step motor drives the throttle valve so that the actual throttle opening is made equal to the final target throttle opening, and the intake pipe pressure is estimated on the basis of the final target throttle opening.

Abstract: In a device for estimating an amount of intake air of an internal combustion engine, wherein an amount of intake air passing through the throttle valve is calculated by using of an upstream side intake air pressure upstream of the throttle valve and a downstream side intake air pressure downstream of the throttle valve, and an amount of intake air supplied into the cylinder is estimated on the basis of the amount of intake air passing through the throttle valve, the upstream side intake air pressure used at the time when the amount of intake air passing through the throttle valve is calculated is detected or calculated to take account of a pressure loss, produced by at least an air-cleaner, from the atmospheric pressure.

Abstract: An intake passage upstream of a throttle valve is divided into a plurality of intake divided-flow conduits, and air flow meters are arranged in the respective intake divided-flow conduits. The throttle opening is obtained, and a throttle valve passing-through air amount, which is an amount of air passing through the throttle valve, is calculated on the basis of the throttle opening. Each air flow meter-detecting intake air amount, which is an intake air amount to be detected by the air flow meter, assuming that air flows through each intake divided-flow conduit by a part of the throttle valve passing-through air amount, the part being determined by a divided-flow ratio of the corresponding intake divided-flow conduit, is estimated, and a total value of the estimated air flow meter-detecting intake air amounts is then estimated. The engine is controlled on the basis of the total air flow meter-detecting intake air amount.

Abstract: A valve characteristic estimation device applied to an internal combustion engine provided with a valve characteristic adjustment mechanism for varying a valve characteristic including at least one of a valve open period and a lift amount of an intake valve. The estimation device detects intake air amount and intake air pressure of the engine, and calculates an estimated value for the valve characteristic based on the detected values of the intake air amount and the intake air pressure. Accordingly, the valve characteristic of the intake valve is accurately estimated.