Abstract: At the time of obtaining a difference in intake air amount between right and left banks in a V-type engine, a target value of a lift-amount/operation-angle-varying mechanism provided for each of the banks is set to a target value at which flow velocity of intake air passing through an intake valve becomes almost sound velocity. In a state in which the flow velocity of intake air passing through the intake valve becomes almost sound velocity, a difference in the intake air amount in the right and left banks is detected and, to reduce the difference, a correction value for a target value of a valve lift is set for each of the banks.

Abstract: In an engine provided with a valve lift amount variable mechanism and a center phase variable mechanism for an intake valve, a region between a region where a flow rate of an intake air passing through the intake valve reaches a sonic speed and a region where an intake air amount does not substantially change relative to a change in an opening area of the intake valve is made to be a learning region. Then, in order to resolve an error in intake air amount in the learning region, a correction value for correcting control process of the valve lift amount variable mechanism is learned. When the learning of the correction value is converged, the learning correction value is corrected with an occupied rate of the valve lift amount variable mechanism in the influence ratio between influences on the two mechanisms in relation to the error.

Abstract: In an engine provided with a valve lift amount variable mechanism and a center phase variable mechanism for an intake valve, a region between a region where a flow rate of an intake air passing through the intake valve reaches a sonic speed and a region where an intake air amount does not substantially change relative to a change in an opening area of the intake valve is made to be a learning region. Then, in order to resolve an error in intake air amount in the learning region, a correction value for correcting control process of the valve lift amount variable mechanism is learned. When the learning of the correction value is converged, the learning correction value is corrected with an occupied rate of the valve lift amount variable mechanism in the influence ratio between influences on the two mechanisms in relation to the error.

Abstract: Evaluation method of evaluating a diagnosing function for a variable valve mechanism of an engine valve in which a desired value used for feedback-control of the variable valve mechanism is subjected to a low-pass filter processing so as to produce a state such that a response delay of the variable valve mechanism is generated, and a transient response of the variable valve mechanism is diagnosed in this state. As a result, if it is not determined that a response delay is generated, it is determined that the diagnosing function is abnormal. An evaluation apparatus for carrying out the method is also disclosed.

Abstract: At the time of obtaining a difference in intake air amount between right and left banks in a V-type engine, a target value of a lift-amount/operation-angle-varying mechanism provided for each of the banks is set to a target value at which flow velocity of intake air passing through an intake valve becomes almost sound velocity. In a state in which the flow velocity of intake air passing through the intake valve becomes almost sound velocity, a difference in the intake air amount in the right and left banks is detected and, to reduce the difference, a correction value for a target value of a valve lift is set for each of the banks.

Abstract: The rotational acceleration of an engine is calculated based on a detection value of an engine rotating speed, the inertia torque to be transmitted to a variable valve mechanism, such as a variable valve timing control mechanism or the like, is calculated based on the rotational acceleration, a correction amount of a manipulated variable for the variable valve mechanism, which is in compliance with the inertia torque, is calculated, and the manipulated variable for the variable valve mechanism is corrected with the correction amount according to the inertia torque, to thereby control the variable valve mechanism based on the corrected manipulated variable.

Abstract: Evaluation of a diagnosis function for diagnosing a transient response of a variable valve mechanism for an engine valve is executed in a manner such that a desired value on the variable valve mechanism is calculated based on testing signals of a rotating speed and a water temperature, that a controlled variable signal for testing indicating a state in which the transient response of the variable valve mechanism is delayed, is generated, and that the diagnostic function for the transient response is evaluated based on whether or not the delay of the transient response is diagnosed on the basis of a correlation between the desired value and a controlled variable signal.

Abstract: A valve timing control apparatus for an internal combustion engine which comprises a variable valve timing mechanism which varies an opening-and-closing timing of an intake valve and/or an exhaust valve of an engine, and in which the opening-and-closing timing at a time of starting the engine is set to a starting time timing which is at a further advance side than a maximum retard timing which is retarded at the maximum, said apparatus characterized in that, at a time of stopping the engine, the variable valve timing mechanism is controlled such that the opening-and-closing timing is made to be the starting time timing.

Abstract: The rotational acceleration of an engine is calculated based on a detection value of an engine rotating speed, the inertia torque to be transmitted to a variable valve mechanism, such as a variable valve timing control mechanism or the like, is calculated based on the rotational acceleration, a correction amount of a manipulated variable for the variable valve mechanism, which is in compliance with the inertia torque, is calculated, and the manipulated variable for the variable valve mechanism is corrected with the correction amount according to the inertia torque, to thereby control the variable valve mechanism based on the corrected manipulated variable.

Abstract: Evaluation method of evaluating a diagnosing function for a variable valve mechanism of an engine valve in which a desired value used for feedback-control of the variable valve mechanism is subjected to a low-pass filter processing so as to produce a state such that a response delay of the variable valve mechanism is generated, and a transient response of the variable valve mechanism is diagnosed in this state. As a result, if it is not determined that a response delay is generated, it is determined that the diagnosing function is abnormal. An evaluation apparatus for carrying out the method is also disclosed.

Abstract: Evaluation of a diagnosis function for diagnosing a transient response of a variable valve mechanism for an engine valve is executed in a manner such that a desired value on the variable valve mechanism is calculated based on testing signals of a rotating speed and a water temperature, that a controlled variable signal for testing indicating a state in which the transient response of the variable valve mechanism is delayed, is generated, and that the diagnostic function for the transient response is evaluated based on whether or not the delay of the transient response is diagnosed on the basis of a correlation between the desired value and a controlled variable signal.

Abstract: Gains of a feedback control of a variable valve mechanism are varied so that a response delay occurs. As a result that a transient response is diagnosed under this state, in the case where the occurrence of response delay is not judged, it is judged that a response diagnosis function is abnormal.

Abstract: A valve timing control apparatus for an internal combustion engine which comprises a variable valve timing mechanism which varies an opening-and-closing timing of an intake valve and/or an exhaust valve of an engine, and in which the opening-and-closing timing at a time of starting the engine is set to a starting time timing which is at a further advance side than a maximum retard timing which is retarded at the maximum, said apparatus characterized in that, at a time of stopping the engine, the variable valve timing mechanism is controlled such that the opening-and-closing timing is made to be the starting time timing.

Abstract: A rotation phase of a camshaft relative to a crankshaft is detected based on a crank angle signal and a cam angle signal, and also the currents or voltages of electromagnetic brakes constituting a variable valve timing mechanism are converted into the rotation phase, to estimate a change in the rotation phase during the rotation phase is detected, based on the rotation phase obtained by converting the currents or voltages.

Abstract: A rotation phase of a camshaft relative to a crankshaft is detected based on a crank angle signal and a cam angle signal, and also the currents or voltages of electromagnetic brakes constituting a variable valve timing mechanism are converted into the rotation phase, to estimate a change in the rotation phase during the rotation phase is detected, based on the rotation phase obtained by converting the currents or voltages.

Abstract: In a variable valve timing mechanism that changes a rotation phase of a camshaft with respect to a crankshaft by an actuator to vary valve timing of engine valves, when a fixed condition of the rotation phase is detected, the actuator is forcibly driven, to generate a torque alternately in an advance direction and a retarded direction of the rotation phase.

Abstract: In a variable valve timing mechanism that changes a rotation phase of a camshaft with respect to a crankshaft by an actuator to vary valve timing of engine valves, when a fixed condition of the rotation phase is detected, the actuator is forcibly driven, to generate a torque alternately in an advance direction and a retarded direction of the rotation phase.