Abstract: The control apparatus for the internal combustion engine increases a fuel injection amount under predetermined conditions, such as after the start of the internal combustion engine, at cold time, at acceleration requiring time, at gear shifting time from a neutral to a D-range, for example. When the fuel injection amount is increased during execution of air/fuel ratio feedback control, the feedback control follows the increase amount, and executes correction corresponding to the increase amount. Then, at the point of time when the correction corresponding to the increase amount is completed, the increase of the fuel injection amount is stopped quickly. Thereby, the increase of the fuel injection amount is not continued unnecessarily, and therefore useless consumption of the fuel can be suppressed. Also, it becomes possible to start other controls early by finishing increase quickly.

Abstract: A canister is furnished to store evaporative fuel. A purge line is furnished to ensure that the canister communicates with an internal combustion engine intake path. The purge line is provided with a D-VSV (purge control valve) that controls the continuity of the purge line. Further, a check valve is furnished to control the pressure propagation from the intake path to the canister at the time of backfiring.

Abstract: A feedback correction coeficient used to perform feedback-control of the fuel injection amount based on the air-fuel ratio of exhaust gas is calculated. A concentration updating based value is set based on the deviation of the oscillation center of the feedback correction coefficiect, and a vapor concentration correction coefficient corresponding to the fuel concentration of purge gas is updated using the concentration updating base value. During the period where the fuel concentration of purge gas is expected to sharply decrease, the concentration updating base value is increased.

Abstract: A device for controlling an internal combustion engine, comprising a variable valve mechanism for varying opening areas (valve lift) or the working angles (valve-opening periods) of at least either the intake valves or the exhaust valves, wherein a pressure in the cylinder is calculated based on the opening area or the working angle of at least either the intake valve or the exhaust valve varied by the variable valve mechanism, and the internal combustion engine is controlled based on the pressure in the cylinder. Upon calculating the pressure in the cylinder based on the opening areas or the working angles of the intake and exhaust valves, it is possible to more suitably control the internal combustion engine based not only upon the peak combustion pressure in the cylinder like when a combustion pressure sensor is used but also upon a pressure in the cylinder at a moment other than the peak combustion pressure.

Abstract: A feedback correction coeficient used to perform feedback-control of the fuel injection amount based on the air-fuel ratio of exhaust gas is calculated. A concentration updating based value is set based on the deviation of the oscillation center of the feedback correction coefficiect, and a vapor concentration correction coefficient corresponding to the fuel concentration of purge gas is updated using the concentration updating base value. During the period where the fuel concentration of purge gas is expected to sharply decrease, the concentration updating base value is increased.

Abstract: A device for controlling an internal combustion engine, comprising a variable valve mechanism for varying opening areas (valve lift) or the working angles (valve-opening periods) of at least either the intake valves or the exhaust valves, wherein a pressure in the cylinder is calculated based on the opening area or the working angle of at least either the intake valve or the exhaust valve varied by the variable valve mechanism, and the internal combustion engine is controlled based on the pressure in the cylinder. Upon calculating the pressure in the cylinder based on the opening areas or the working angles of the intake and exhaust valves, it is possible to more suitably control the internal combustion engine based not only upon the peak combustion pressure in the cylinder like when a combustion pressure sensor is used but also upon a pressure in the cylinder at a moment other than the peak combustion pressure.

Abstract: A fuel tank is provided with an atmospheric air introduction hole so that the fuel tank communicates with the outside. As a result, the interior of the fuel tank is maintained at a pressure level between substantially atmospheric air pressure and positive pressure. A canister may be connected to the atmospheric air introduction hole. When an internal combustion engine starts up, the fuel tank communicates with an intake path. Internal combustion engine startup places the intake path under negative pressure. Under negative pressure, fuel vapor is supplied to the intake path from the fuel tank whose pressure level is between substantially atmospheric air pressure and positive pressure.

Abstract: A device for controlling an internal combustion engine, comprising a variable valve mechanism for varying opening areas (valve lift) or the working angles (valve-opening periods) of at least either the intake valves or the exhaust valves, wherein a pressure in the cylinder is calculated based on the opening area or the working angle of at least either the intake valve or the exhaust valve varied by the variable valve mechanism, and the internal combustion engine is controlled based on the pressure in the cylinder. Upon calculating the pressure in the cylinder based on the opening areas or the working angles of the intake and exhaust valves, it is possible to more suitably control the internal combustion engine based not only upon the peak combustion pressure in the cylinder like when a combustion pressure sensor is used but also upon a pressure in the cylinder at a moment other than the peak combustion pressure.

Abstract: An evaporative emission control system detects an opening failure of a purge control valve that controls the amount of purge gas flowing from a canister into an intake passage of the engine, and determines whether a significant shift occurs in an air/fuel ratio feedback factor when the opening failure is detected. If the air/fuel ratio feedback factor is shifted to the rich side, a rich-side initial value is set to a vapor concentration learned value, and, if the feedback factor is shifted to the lean side, a lean-side initial value is set to the vapor concentration learned value. These initial values give larger changes to the vapor concentration learned value than update amounts by which the learned value is updated during normal learning control.

Abstract: A device for controlling an internal combustion engine, comprising a variable valve mechanism for varying opening areas (valve lift) or the working angles (valve-opening periods) of at least either the intake valves or the exhaust valves, wherein a pressure in the cylinder is calculated based on the opening area or the working angle of at least either the intake valve or the exhaust valve varied by the variable valve mechanism, and the internal combustion engine is controlled based on the pressure in the cylinder. Upon calculating the pressure in the cylinder based on the opening areas or the working angles of the intake and exhaust valves, it is possible to more suitably control the internal combustion engine based not only upon the peak combustion pressure in the cylinder like when a combustion pressure sensor is used but also upon a pressure in the cylinder at a moment other than the peak combustion pressure.

Abstract: A canister is furnished to store evaporative fuel. A purge line is furnished to ensure that the canister communicates with an internal combustion engine intake path. The purge line is provided with a D-VSV (purge control valve) that controls the continuity of the purge line. Further, a check valve is furnished to control the pressure propagation from the intake path to the canister at the time of backfiring.

Abstract: A device for controlling an internal combustion engine, comprising a variable valve mechanism for varying opening areas (valve lift) or the working angles (valve-opening periods) of at least either the intake valves or the exhaust valves, wherein a pressure in the cylinder is calculated based on the opening area or the working angle of at least either the intake valve or the exhaust valve varied by the variable valve mechanism, and the internal combustion engine is controlled based on the pressure in the cylinder. Upon calculating the pressure in the cylinder based on the opening areas or the working angles of the intake and exhaust valves, it is possible to more suitably control the internal combustion engine based not only upon the peak combustion pressure in the cylinder like when a combustion pressure sensor is used but also upon a pressure in the cylinder at a moment other than the peak combustion pressure.

Abstract: A device for controlling an internal combustion engine, comprising a variable valve mechanism for varying opening areas (valve lift) or the working angles (valve-opening periods) of at least either the intake valves or the exhaust valves, wherein a pressure in the cylinder is calculated based on the opening area or the working angle of at least either the intake valve or the exhaust valve varied by the variable valve mechanism, and the internal combustion engine is controlled based on the pressure in the cylinder. Upon calculating the pressure in the cylinder based on the opening areas or the working angles of the intake and exhaust valves, it is possible to more suitably control the internal combustion engine based not only upon the peak combustion pressure in the cylinder like when a combustion pressure sensor is used but also upon a pressure in the cylinder at a moment other than the peak combustion pressure.

Abstract: A device for controlling an internal combustion engine, comprising a variable valve mechanism for varying opening areas (valve lift) or the working angles (valve-opening periods) of at least either the intake valves or the exhaust valves, wherein a pressure in the cylinder is calculated based on the opening area or the working angle of at least either the intake valve or the exhaust valve varied by the variable valve mechanism, and the internal combustion engine is controlled based on the pressure in the cylinder. Upon calculating the pressure in the cylinder based on the opening areas or the working angles of the intake and exhaust valves, it is possible to more suitably control the internal combustion engine based not only upon the peak combustion pressure in the cylinder like when a combustion pressure sensor is used but also upon a pressure in the cylinder at a moment other than the peak combustion pressure.

Abstract: An evaporative emission control system includes a canister for collecting fuel vapor from a fuel tank, and a purge control valve disposed between the canister and the intake passage of the engine. A controller of the system determines a failure of the purge control valve, executes a purging process by opening the purge control valve, executes a learning process for learning the fuel concentration of the purge gas, and executes a correcting process for correcting the amount of fuel injected into the engine based on the learned value of the fuel concentration. When the purge control valve is normal and conditions for execution of purge control are satisfied, the controller requests execution of the purging process, learning process and the correcting process. When an open failure occurs in the purge control valve, the controller always requests execution of the learning process and the correcting process.

Abstract: The control apparatus for the internal combustion engine increases a fuel injection a mount under predetermined conditions, such as after the start of the internal combustion engine, at cold time, at acceleration requiring time, at gear shifting time from a neutral to a D-range, for example. When the fuel injection amount is increased during execution of air/fuel ratio feedback control, the feedback control follows the increase amount, and executes correction corresponding to the increase amount. Then, at the point of time when the correction corresponding to the increase amount is completed, the increase of the fuel injection amount is stopped quickly. Thereby, the increase of the fuel injection amount is not continued unnecessarily, and therefore useless consumption of the fuel can be suppressed. Also, it becomes possible to start other controls early by finishing increase quickly.

Abstract: A fuel tank is provided with an atmospheric air introduction hole so that the fuel tank communicates with the outside. As a result, the interior of the fuel tank is maintained at a pressure level between substantially atmospheric air pressure and positive pressure. A canister may be connected to the atmospheric air introduction hole. When an internal combustion engine starts up, the fuel tank communicates with an intake path. Internal combustion engine startup places the intake path under negative pressure. Under negative pressure, fuel vapor is supplied to the intake path from the fuel tank whose pressure level is between substantially atmospheric air pressure and positive pressure.

Abstract: An evaporative emission control system detects an opening failure of a purge control valve that controls the amount of purge gas flowing from a canister into an intake passage of the engine, and determines whether a significant shift occurs in an air/fuel ratio feedback factor when the opening failure is detected. If the air/fuel ratio feedback factor is shifted to the rich side, a rich-side initial value is set to a vapor concentration learned value, and, if the feedback factor is shifted to the lean side, a lean-side initial value is set to the vapor concentration learned value. These initial values give larger changes to the vapor concentration learned value than update amounts by which the learned value is updated during normal learning control.

Abstract: An evaporative emission control system includes a canister for collecting fuel vapor from a fuel tank, and a purge control valve disposed between the canister and the intake passage of the engine. A controller of the system determines a failure of the purge control valve, executes a purging process by opening the purge control valve, executes a learning process for learning the fuel concentration of the purge gas, and executes a correcting process for correcting the amount of fuel injected into the engine based on the learned value of the fuel concentration. When the purge control valve is normal and conditions for execution of purge control are satisfied, the controller requests execution of the purging process, learning process and the correcting process. When an open failure occurs in the purge control valve, the controller always requests execution of the learning process and the correcting process.

Abstract: An evaporated fuel processing apparatus for an internal combustion engine is provided which includes a canister that traps fuel vapors generated in a fuel tank, and a purge control valve disposed between the canister and an intake passage of the internal combustion engine. A controller of the apparatus determines (a) a quantity of purge gas that passes through the purge control valve, (b) a fuel injection amount correction coefficient for reducing a deviation of an actual air-fuel ratio from a target air-fuel ratio due to the purge gas, (c) a fresh air ratio that represents a ratio of purge air contained in the purge gas to the purge gas, based on the fuel injection amount correction coefficient, and (d) a quantity of the purge air based on the quantity of the purge gas and the fresh air ratio. The controller then controls the internal combustion engine based on the quantity of the purge air.