Abstract: A variable valve mechanism performs a valve lift switching operation for an intake valve. ECU defines valve lift switching characteristics corresponding to the engine operating region and executes the valve lift switching operation based on the switching characteristics. ECU calculates a parameter fluctuation amount of an engine occurring in response to the valve lift switching operation, and corrects the valve lift switching characteristics when the calculated parameter fluctuation amount exceeds a predetermined judgment value.

Abstract: A method is described for estimating cylinder airflow in engines that operate with manifold pressure near atmospheric pressure to compensate for degraded sensor response at such conditions. The method uses an adaptive approach that is updated under preselected engine operating conditions to thereby allow improved accuracy across a variety of engine operation.

Abstract: In an control apparatus and a control method for an internal combustion engine with a variable valve-characteristic mechanism that changes a valve characteristic that includes at least one of the duration and the maximum lift of an intake valve, the operating position of the mechanism is detected, and the mechanism is controlled so that a value of the valve characteristic corresponding to the operating position is equal to a target value corresponding to an engine operating state. After the target value is changed so that the intake valve opens/closes in accordance with a specific value of the valve characteristic, the operating position of the mechanism is learned as a reference position for the control of the valve characteristic. An intake-air-amount adjustment device upstream of the intake valve is controlled to offset the change in the amount of intake air caused by changing the target value when the reference position is learned.

Abstract: The amount of air to be introduced is controlled for each cylinder, whereby it is intended to make it possible to control the torque generated in each cylinder, perform an ultra-lean burn operation, purify the exhaust gas, and increase the output of an engine. An air flow control valve adapted to be on-off controlled in accordance with an operated quantity of an accelerator pedal is disposed in each branch pipe or intake port. The air flow control valve may be a throttle valve disposed in each branch pipe or it may be a variable intake valve for opening and closing the intake port.

Abstract: An engine system includes an engine and an engine control unit. The engine includes an intake valve that opens and closes the opening of a cylinder, a valve actuator that drives the intake valve and can arbitrarily control the lift amount of the intake valve, an intake passage that introduces air and fuel into the cylinder through the opening of the cylinder, and a throttle valve provided to open and close the opening of the intake passage and control the quantity of air to be introduced into the cylinder in response to a load required by a driver. During intake operation in substantially all the load states of the engine, the valve actuator is controlled so that the opening area of the opening determined by the lift amount of the intake valve is not less than the opening area of the opening determined by the opening degree of the throttle valve.

Abstract: A method for diagnosing the operational state of a variable valve lift device (VVL) is provided. The method includes providing a first signal indicative of an estimated position of the VVL, the first signal having a first signal-to-noise ratio; determining that the first signal represents either a first condition indicating that the VVL is operating in one of two modes of operation, a second condition indicating that the VVL is not operating in the two modes of operation, and a third condition where the first signal is not in the first or second conditions; and adjusting a camshaft phase angle when the first signal is in the third condition so that the first signal has a second signal-to-noise ratio, wherein the second signal-to-noise ratio is greater than the first signal-to-noise ratio, whereby the operational state of the VVL is identified as one of the first and second conditions.

Abstract: In a control apparatus for controlling an intake air amount of an engine by variably controlling a lift amount of an intake valve, when a variable valve lift mechanism is failed, the control is switched to a control of the intake air amount based on an opening degree of a throttle valve, and also the opening degree of the throttle valve is restricted within an upper limit value in order to ensure a negative pressure utilized by a brake booster.

Abstract: It is an object of the present invention to provide a drive unit for a direct-acting valve for internal combustion engines by which a quiet internal combustion engine can be obtained with noise suppressed. This system comprises an inlet valve 8 arranged slidably near an inlet port 4 of an internal combustion engine 12 for driving the inlet port to open and close, an electromagnetic actuator 1 that drives the inlet valve to open and close, and a current control unit 11 that controls a driving current supplied to the electromagnetic actuator. The current control unit continuously supplies the driving current, having a controlled variable value, to the electromagnetic actuator based on the operation condition of the internal combustion engine.

Abstract: In an internal combustion engine provided with a variable valve mechanism that varies at least a valve operating characteristic (valve lift amount and the like) of an intake valve, a target intake air amount equivalent to a target torque is set based on operating conditions of the engine, to calculate a target volume flow ratio by dividing the target intake air amount by an engine rotation speed and total cylinder volume. The target volume flow ratio is corrected according to closing timing of the intake valve. If the valve lift amount of the intake valve is in a low valve lift region, the target volume flow ratio is further corrected according to the valve lift amount, and the post corrected target volume flow ratio is converted into a valve opening area of the intake valve to be set as a target valve opening area. Then, based on the target valve opening area, a target valve operating characteristic of the intake valve is set.

Abstract: An intake control apparatus is configured to control a variable valve operating mechanism and an opening degree of a throttle valve. The variable valve operating mechanism varies the valve lift characteristic of the intake valves to control the intake air amount into the cylinders of the engine. The throttle valve produces a negative pressure inside the collector, but in a valve control region including medium loads, the pressure inside the collector is fixed at a weak negative pressure and the intake air amount is controlled by varying the valve lift characteristic of the intake valves. In an internal EGR priority region of low loads, the negative pressure is strengthened somewhat and the lift/duration of the intake valves is increased. When the engine is cold, the negative pressure is adjusted to be close to atmospheric pressure and the lift/duration of the intake valves is reduced.

Abstract: A method is described for estimating cylinder airflow in engines that operate with manifold pressure near atmospheric pressure to compensate for degraded sensor response at such conditions. The method uses an adaptive approach that is updated under preselected engine operating conditions to thereby allow improved accuracy across a variety of engine operation.

Abstract: A method is provided for controlling an engine having an intake manifold and an outlet control device coupled to the manifold for controlling flow exiting the manifold and entering at least one cylinder of the engine. The engine further includes an inlet control device for controlling flow entering the manifold. The method includes providing an engine command; calculating a desired cylinder charge based on said command; and adjusting the outlet control device to provide said desired cylinder charge. The engine command may be, for example, a driver command, such as a driver torque command. Further, the outlet control device may be implement in with a variety of mechanisms. For example, in one embodiment the outlet control device is a valve of the engine having a variable lift. In one embodiment the outlet device is a valve having variable timing. Likewise, the inlet device may be adjusted in response to a variety of parameters.

Abstract: In an internal combustion engine provided with a variable valve mechanism that varies a valve operating characteristic (valve lift amount and valve operating angle) of an intake valve, the valve operating characteristic of the intake valve is detected and an intake air amount controlled by the intake valve is calculated based on the detected valve operating characteristic. Then, a change (change rate, change amount) between the newest intake air amount calculation value and a past intake air amount calculation value is calculated, and the newest engine controlled variable is calculated based on the change and engine controlled variable (basic fuel injection quantity and the like) set in the past, and then the calculated newest engine controlled variable is output for executing an engine control.

Abstract: A rate of cylinder-to-cylinder variations in an intake air quantity is calculated, and learned as a learning value based on an output from an airflow meter when a predetermined condition is met. The predetermined condition is set at a preferable condition for learning the rate of cylinder-to-cylinder variations. Subsequently, the rate of cylinder-to-cylinder variations is estimated based on the learning value when the predetermined condition is not met. Thus, cylinder-to-cylinder variations of an engine are accurately obtained in almost all the operating ranges, so that the measurement of the cylinder-by-cylinder intake air quantity with high degree of accuracy is achieved.

Abstract: An intake control apparatus is configured to control a variable valve operating mechanism and an opening degree of a throttle valve. The variable valve operating mechanism varies the valve lift characteristic of the intake valves to control the intake air amount into the cylinders of the engine. The throttle valve produces a negative pressure inside the collector, but in a valve control region including medium loads, the pressure inside the collector is fixed at a weak negative pressure and the intake air amount is controlled by varying the valve lift characteristic of the intake valves. In an internal EGR priority region of low loads, the negative pressure is strengthened somewhat and the lift/duration of the intake valves is increased. When the engine is cold, the negative pressure is adjusted to be close to atmospheric pressure and the lift/duration of the intake valves is reduced.

Abstract: It is an object of the present invention to provide a drive unit for a direct-acting valve for internal combustion engines, by which quiet internal combustion engine can be obtained, with the noise suppressed. This system comprises an inlet valve 8 arranged slidably near an inlet port 4 of an internal combustion engine 12 for driving the inlet port to open and close, an electromagnetic actuator 1 that drives the inlet valve to open and close, and a current control unit 11 that controls a driving current supplied to the electromagnetic actuator, wherein the current control unit continuously supplies the driving current having a specific value to the electromagnetic actuator, based on the operation condition of the internal combustion engine.

Abstract: In an internal combustion engine provided with a variable valve mechanism that varies a valve operating characteristic of an intake valve, the valve operating characteristic of the intake valve is detected, and a flow loss coefficient and an effective opening area of the intake valve are calculated based on the valve operating characteristic, to calculate an intake air flow amount in a cylinder portion based on parameters inclusive of the calculated flow loss coefficient and effective opening area.

Abstract: If during a specific steady operation state of an engine, the actual intake pipe pressure is different from a target intake pipe pressure set during the specific steady operation state, a first correction amount for the throttle valve control value is calculated by causing the actual intake pipe pressure to become equal to the target intake pipe pressure. If at this time the actual amount of intake air is still different from a target amount of intake air set during the specific steady operation state, a second correction amount for the variable valve control value is calculated by causing the actual amount of a intake air to become equal to the target amount of intake air. The second correction amount is used to further correct the throttle valve control value corrected by the first correction amount.

Abstract: A control method of an internal combustion engine with which braking force while reducing the speed of the motor vehicle can be established by generating pumping loss effectively by using a variable valve mechanism enabling to control arbitrarily the open-close timing and the lift amount of air intake and exhaust valves of the engine. When the break step-on force detection means detects a step-on force on a brake and an operation of the anti-lock brake system is selected, at least one of the intake valve or the exhaust valve is made close, another one not closed of the intake valve or the exhaust valve is made open once in a single revolution of the engine while a piston moves from a top dead center to a bottom dead center, and a lift of the valve is controlled to be a designated value.

Abstract: A method of affecting a mixture formation and motion of a charge in a cylinder of an externally ignited internal-combustion engine during a suction cycle of a gas intake valve of the cylinder. The suction cycle has a first cycle portion and a second cycle portion; the second cycle portion constitutes an end portion (leading and/or trailing end portion) of the suction cycle. The gas intake valve has, during the first suction cycle, a first open position at full valve stroke in which the gas intake valve has a fully open cross-sectional flow passage area. The method includes the step of maintaining the gas intake valve in a second open position at a partial stroke of the gas intake valve during the second cycle portion. The partial stroke is less than one half of the full stroke, and in the second open position the gas intake valve has a partially open cross-sectional flow passage area.

Abstract: A control method of an internal combustion engine with which braking force while reducing the speed of the motor vehicle can be established by generating pumping loss effectively by using a variable valve mechanism enabling to control arbitrarily the open-close timing and the lift amount of air intake and exhaust valves of the engine. When the break step-on force detection means detects a step-on force on a brake and an operation of the anti-lock brake system is selected, at least one of the intake valve or the exhaust valve is made close, another one not closed of the intake valve or the exhaust valve is made open once in a single revolution of the engine while a piston moves from a top dead center to a bottom dead center, and a lift of the valve is controlled to be a designated value.

Abstract: An exhaust braking system used with an internal combustion engine has an inlet valve an exhaust valve, an exhaust brake connected in an exhaust system connected with the exhaust valve, and an actuator connected in a fluid circuit with the exhaust brake. The exhaust brake is closed to retard the rotational speed of the engine and an induction valve connected in an induction passage to the inlet valve and in the fluid circuit with the exhaust brake is also operated to facilitate engine speed retardation. Timing apparatus is connected with the induction valve and exhaust brake to ensure the exhaust brake is closed no later than the closing of the induction valve, while a non-return valve is connected in the induction passage to facilitating an increase in pressure within a piston cylinder of the engine and hence increase the engine retardation. A pressure sensitive device connected in the induction passage or exhaust system controls the maximum pressure of the braking system.