Abstract: An internal EGR parameter estimating device is configured to estimate the internal EGR quantity based on the quantity of blow-by gas that blows by during an overlap period when both the intake valve(s) and the exhaust valve(s) are open. The blow-by gas quantity is calculated based on the intake air pressure and the exhaust gas pressure during the overlap period and the effective cross sectional area opening formed by the intake and exhaust valves. The overlap period is divided into intervals of a prescribed period and the interval cross sectional area opening during each interval is calculated.

Abstract: An internal EGR parameter estimating device is configured to estimate the internal EGR quantity based on the quantity of blow-by gas that blows by during an overlap period when both the intake valve(s) and the exhaust valve(s) are open. The blow-by gas quantity is calculated based on the intake air pressure and the exhaust gas pressure during the overlap period and the effective cross sectional area opening formed by the intake and exhaust valves. The overlap period is divided into intervals of a prescribed period and the interval cross sectional area opening during each interval is calculated.

Abstract: Engine cranking control is ended when it is detected that the battery voltage for driving the starter is lowered to at least as low as a starter drive judgment value and thereafter, returns to at least a starter stop judgment value during the engine cranking control that is started on condition that an engine is rotating. A start for driving a starter and a stop of driving the starter can be distinguished based on battery voltage where the battery voltage recovers due to a rapid reduction of consuming current and a rapid increase of a generating current when a driver recognizes an engine combustion completion and stops a starter driving. As a result, on increase of an engine friction, the cranking control is accurately ended, preventing deterioration of a fuel economy and excess exhaust gas emission.

Abstract: A controller (31) of a knocking index value calculation device in a spark ignition engine (1) determines operating conditions of the engine (1), estimates an in-cylinder pressure at a reference crank angle, which is set at a predetermined crank position after compression top dead center, using these operating conditions, estimates a temperature of unburned gas in the cylinder at the reference crank angle using these operating conditions, and calculates a knocking index value using the in-cylinder pressure and unburned gas temperature.

Abstract: An internal exhaust gas recirculation amount estimation system calculates an in-cylinder temperature at an exhaust valve closure timing, an in-cylinder pressure at the exhaust valve closure timing, and a gas constant corresponding to a change in a composition of exhaust gas, based on an air-fuel mixture ratio. An exhaust valve closure timing in-cylinder residual gas amount is calculated based on at least the in-cylinder temperature, the in-cylinder pressure, and the gas constant. Also calculated is a valve overlap period blow-back gas amount, which is defined as a quantity of gas flow from one of intake and exhaust ports via a combustion chamber to the other port during a valve overlap period. An internal exhaust gas recirculation amount is calculated based on the exhaust valve closure timing in-cylinder residual gas amount and the valve overlap period blow-back gas amount.

Abstract: An invention that judges whether an engine is being cranked by a starter based on the conditions that a prior cranking control has ended, the engine rotates at or less than a limit rotation velocity leading to an engine stall, and a battery voltage falls to or below a predetermined value. When such conditions are met, then engine cranking control is started. The engine can be shifted to the cranking control without an input signal from a starter switch and the engine can be promptly cranked.

Abstract: A controller (31) of a knocking index value calculation device in a spark ignition engine (1) determines operating conditions of the engine (1), estimates an in-cylinder pressure at a reference crank angle, which is set at a predetermined crank position after compression top dead center, using these operating conditions, estimates a temperature of unburned gas in the cylinder at the reference crank angle using these operating conditions, and calculates a knocking index value using the in-cylinder pressure and unburned gas temperature.

Abstract: An internal exhaust gas recirculation amount estimation system calculates an in-cylinder temperature at an exhaust valve closure timing, an in-cylinder pressure at the exhaust valve closure timing, and a gas constant corresponding to a change in a composition of exhaust gas, based on an air-fuel mixture ratio. An exhaust valve closure timing in-cylinder residual gas amount is calculated based on at least the in-cylinder temperature, the in-cylinder pressure, and the gas constant. Also calculated is a valve overlap period blow-back gas amount, which is defined as a quantity of gas flow from one of intake and exhaust ports via a combustion chamber to the other port during a valve overlap period. An internal exhaust gas recirculation amount is calculated based on the exhaust valve closure timing in-cylinder residual gas amount and the valve overlap period blow-back gas amount.

Abstract: A control apparatus controls the opening and closing timings of the intake and exhaust valves and the fuel injection timing. When the water temperature of the engine is equal to or below a predetermined value, the exhaust valve closes before the top dead center, and the intake valve opens after the top dead center. At the same time, if the pressure inside the intake passage is equal to or below a predetermined value, the fuel injection is conducted during the intake process. Furthermore, the intake fuel injection timing is changed according to the rotational speed of the engine. In this manner, the vaporization of the injected fuel is promoted, and stability of the combustion is improved. Also the exhaust emission is improved, while the fuel consumption is reduced.

Abstract: Engine cranking control is ended when it is detected that the battery voltage for driving the starter is lowered to at least as low as a starter drive judgement value and thereafter, returns to at least a starter stop judgement value during the engine cranking control that is started on condition that an engine is rotating. A start for driving a starter and a stop of driving the starter can be distinguished based on battery voltage where the battery voltage recovers due to a rapid reduction of consuming current and a rapid increase of a generating current when a driver recognizes an engine combustion completion and stops a starter driving. As a result, on increase of an engine friction, the cranking control is accurately ended, preventing deterioration of a fuel economy and excess exhaust gas emission.

Abstract: An invention that judges whether an engine is being cranked by a starter based on the conditions that a prior cranking control has ended, the engine rotates at or less than a limit rotation velocity leading to an engine stall, and a battery voltage falls to or below a predetermined value. When such conditions are met, then engine cranking control is started. The engine can be shifted to the cranking control without an input signal from a starter switch and the engine can be promptly cranked.

Abstract: The startup time of an engine is shortened by performing initial fuel injection after the start of cranking on a cylinder undergoing an intake stroke and a cylinder undergoing an exhaust stroke. After the initial fuel injection, HC emissions are suppressed by performing fuel injection in cylinders undergoing an exhaust stroke. Furthermore when it is determined that initial combustion has not occurred after the initial fuel injection, an additional injection is performed on the cylinder undergoing an intake stroke. In this manner, it is possible to minimize increases in the startup time and adverse effects on exhaust emissions.

Abstract: In a four-stroke cycle multi-cylinder internal combustion engine (2), a controller (1) controls fuel injectors (8) to inject fuel for the cylinder (#1) in the intake stroke immediately after the first cylinder-stroke identification is performed. Due to this fuel injection control, the fuel is necessarily injected before the first combustion occasion at any cylinder (#1-#4), cylinder dependent fluctuation of air-fuel ratio when the first combustion takes place in the respective cylinders (#1-#4) is prevented. Further, in a predetermined low temperature range, the controller (1) controls fuel injectors (8) to perform a preliminary fuel injection for all the cylinders (#1-#4) before the first cylinder-stroke identification, so the fuel amount required for the first combustion is ensured for all the cylinders (#1-#4).

Abstract: An internal combustion engine (2) provided with a starter motor sequentially performs combustion of fuel in a plurality of cylinders (#1-#4). Each cylinder is provided with an intake port (7) and a fuel injector (8) to inject fuel in the intake port (7) and repeatedly performs an intake stroke, compression stroke, expansion stroke and an exhaust stroke. A sensor (9, 11) generates a signal identifying a cylinder in a specific position in a specific stroke and the controller (1) executes a cylinder-stroke identification in response to the signal. Upon the first execution of the cylinder-stroke identification when the engine is cranked, a fuel injection is performed for a cylinder in the intake stroke and for a cylinder in the exhaust stroke simultaneously so as to ensure the fuel supply amount required for the first combustion in each cylinder.

Abstract: A fuel injection control device for an internal combustion engine is provided with a controller functions to command the fuel injectors for a cylinder in the exhaust stroke and for a cylinder in the intake stroke to simultaneously perform a primary fuel injection, when the first cylinder-stroke identification is performed, if the engine temperature is higher than a predetermined temperature. The controller further functions to command the fuel injector only for a cylinder in the intake stroke to perform a primary fuel injection, when the first cylinder-stroke identification is performed, if the engine temperature is less than the predetermined temperature. Thus the startup time of the engine is shortened and the stability of startup is ensured at normal, low, or extremely low temperatures.

Abstract: An internal combustion engine (2) provided with a starter motor sequentially performs combustion of fuel in a plurality of cylinders (#1-#4). Each cylinder is provided with an intake port (7) and a fuel injector (8) to inject fuel in the intake port (7) and repeatedly performs an intake stroke, compression stroke, expansion stroke and an exhaust stroke. A sensor (9, 11) generates a signal identifying a cylinder in a specific position in a specific stroke and the controller (1) executes a cylinder-stroke identification in response to the signal. Upon the first execution of the cylinder-stroke identification when the engine is cranked, a fuel injection is performed for a cylinder in the intake stroke and for a cylinder in the exhaust stroke similtaneously so as to ensure the fuel supply amount required for the first combustion in each cylinder.

Abstract: A fuel injection control device for an internal combustion engine is provided with a controller functions to command the fuel injectors for a cylinder in the exhaust stroke and for a cylinder in the intake stroke to simultaneously perform a primary fuel injection, when the first cylinder-stroke identification is performed, if the engine temperature is higher than a predetermined temperature. The controller further functions to command the fuel injector only for a cylinder in the intake stroke to perform a primary fuel injection, when the first cylinder-stroke identification is performed, if the engine temperature is less than the predetermined temperature. Thus the startup time of the engine is shortened and the stability of startup is ensured at normal, low, or extremely low temperatures.

Abstract: The startup time of an engine is shortened by performing initial fuel injection after the start of cranking on a cylinder undergoing an intake stroke and a cylinder undergoing an exhaust stroke. After the initial fuel injection, HC emissions are suppressed by performing fuel injection in cylinders undergoing an exhaust stroke. Furthermore when it is determined that initial combustion has not occurred after the initial fuel injection, an additional injection is performed on the cylinder undergoing an intake stroke. In this manner, it is possible to minimize increases in the startup time and adverse effects on exhaust emissions.

Abstract: In a four-stroke cycle multi-cylinder internal combustion engine (2), a controller (1) controls fuel injectors (8) to inject fuel for the cylinder (#1) in the intake stroke immediately after the first cylinder-stroke identification is performed. Due to this fuel injection control, the fuel is necessarily injected before the first combustion occasion at any cylinder (#1-#4), cylinder dependent fluctuation of air-fuel ratio when the first combustion takes place in the respective cylinders (#1-#4) is prevented. Further, in a predetermined low temperature range, the controller (1) controls fuel injectors (8) to perform a preliminary fuel injection for all the cylinders (#1-#4) before the first cylinder-stroke identification, so the fuel amount required for the first combustion is ensured for all the cylinders (#1-#4).

Abstract: A control apparatus controls the opening and closing timings of the intake and exhaust valves and the fuel injection timing. When the water temperature of the engine is equal to or below a predetermined value, the exhaust valve closes before the top dead center, and the intake valve opens after the top dead center. At the same time, if the pressure inside the intake passage is equal to or below a predetermined value, the fuel injection is conducted during the intake process. Furthermore, the intake fuel injection timing is changed according to the rotational speed of the engine. In this manner, the vaporization of the injected fuel is promoted, and stability of the combustion is improved. Also the exhaust emission is improved, while the fuel consumption is reduced.