Abstract: The internal combustion engine (1) has a throttle (23) for controlling an intake air amount and performs start-up through cranking. The starter switch (36) detects cranking initiation, and the crank angle sensor (33, 34) detects the number of revolutions of the engine. The controller (31) drives the throttle (23) in a closed position along with the cranking initiation. The controller (31) can obtain both the intake negative pressure for promoting vaporization of fuel and the intake air amount necessary to maintain the idle rotation speed by counting the number of strokes or the number of revolutions of the internal combustion engine (1) from the cranking initiation and opening the throttle (23) from the closed position as the count number reaches a predetermined number.

Abstract: When an intermediate lock by an intermediate lock mechanism is released, one of two lock keys, which restricts a shift in a direction opposite to a direction that valve timing of an intake valve has been controlled by controlling the valve timing of the intake valve to a phase-advance side with respect to an intermediate lock position, is pulled out of an engaging recessed portion. Thereafter, the other of the two lock keys is pulled out of an engaging recessed portion by controlling the valve timing of the intake valve to a phase-retard side with respect to the intermediate lock position. Therefore, the intermediate lock by the intermediate lock mechanism can be released, while avoiding the lock keys from being pushed against the respective engaging recessed portions.

Abstract: Intermediate position feedback control is executed when valve timing of an intake valve is at an intermediate lock position, an intermediate lock is needed, and an engine revolution speed is greater than a first engine revolution speed R1. Forced lock control is executed when the valve timing of the intake valve is at the intermediate lock position, the intermediate lock is needed, the engine revolution speed is less than the first engine revolution speed R1, and the intermediate position feedback control is not being executed. As a result, even when the engine revolution speed increases in the presence of a demand that the valve timing needs to be in the intermediate lock position, it is possible to maintain the valve timing at the intermediate lock position.

Abstract: The internal combustion engine (1) has a throttle (23) for controlling an intake air amount and performs start-up through cranking. As the cranking is initiated, an atmospheric pressure is detected and an initial opening is set accordingly. The controller (31) controls the throttle (23) to the initial opening when the cranking is initiated, and controls the throttle to start to increase the throttle opening from the initial opening at a predetermined timing after the cranking initiation. By setting the initial opening based on one or both of the atmospheric pressure and the temperature at the time of cranking initiation, the intake negative pressure and the intake air amount are optimized.

Abstract: To achieve an intermediate lock state in a short period when an engine is stopped and improve the accuracy of confirmation of the intermediate lock state, an engine valve timing control apparatus includes a variable valve timing mechanism configured to vary engine valve timing, and an intermediate lock mechanism configured to restrict relative rotation positions of a first and a second rotor of the valve timing mechanism at an intermediate lock position for starting the engine. Upon detection of an engine stop request, the valve timing mechanism and the intermediate lock mechanism are driven and controlled for establishing an intermediate lock state. When a predetermined period from detection of the engine stop request has expired without detecting the intermediate lock state within the predetermined period, an engine stopping process is executed. Even after the engine stopping process has been executed, monitoring of the intermediate lock state is continued.

Abstract: Intermediate position feedback control is executed when valve timing of an intake valve is at an intermediate lock position, an intermediate lock is needed, and an engine revolution speed is greater than a first engine revolution speed R1. Forced lock control is executed when the valve timing of the intake valve is at the intermediate lock position, the intermediate lock is needed, the engine revolution speed is less than the first engine revolution speed R1, and the intermediate position feedback control is not being executed. As a result, even when the engine revolution speed increases in the presence of a demand that the valve timing needs to be in the intermediate lock position, it is possible to maintain the valve timing at the intermediate lock position.

Abstract: When an intermediate lock by an intermediate lock mechanism is released, one of two lock keys, which restricts a shift in a direction opposite to a direction that valve timing of an intake valve has been controlled by controlling the valve timing of the intake valve to a phase-advance side with respect to an intermediate lock position, is pulled out of an engaging recessed portion. Thereafter, the other of the two lock keys is pulled out of an engaging recessed portion by controlling the valve timing of the intake valve to a phase-retard side with respect to the intermediate lock position. Therefore, the intermediate lock by the intermediate lock mechanism can be released, while avoiding the lock keys from being pushed against the respective engaging recessed portions.

Abstract: To achieve an intermediate lock state in a short period when an engine is stopped and improve the accuracy of confirmation of the intermediate lock state, an engine valve timing control apparatus includes a variable valve timing mechanism configured to vary engine valve timing, and an intermediate lock mechanism configured to restrict relative rotation positions of a first and a second rotor of the valve timing mechanism at an intermediate lock position for starting the engine. Upon detection of an engine stop request, the valve timing mechanism and the intermediate lock mechanism are driven and controlled for establishing an intermediate lock state. When a predetermined period from detection of the engine stop request has expired without detecting the intermediate lock state within the predetermined period, an engine stopping process is executed. Even after the engine stopping process has been executed, monitoring of the intermediate lock state is continued.

Abstract: The internal combustion engine (1) has a throttle (23) for controlling an intake air amount and performs start-up through cranking. As the cranking is initiated, an atmospheric pressure is detected and an initial opening is set accordingly. The controller (31) controls the throttle (23) to the initial opening when the cranking is initiated, and controls the throttle to start to increase the throttle opening from the initial opening at a predetermined timing after the cranking initiation. By setting the initial opening based on one or both of the atmospheric pressure and the temperature at the time of cranking initiation, the intake negative pressure and the intake air amount are optimized.

Abstract: The internal combustion engine (1) has a throttle (23) for controlling an intake air amount and performs start-up through cranking. The starter switch (36) detects cranking initiation, and the crank angle sensor (33, 34) detects the number of revolutions of the engine. The controller (31) drives the throttle (23) in a closed position along with the cranking initiation. The controller (31) can obtain both the intake negative pressure for promoting vaporization of fuel and the intake air amount necessary to maintain the idle rotation speed by counting the number of strokes or the number of revolutions of the internal combustion engine (1) from the cranking initiation and opening the throttle (23) from the closed position as the count number reaches a predetermined number.

Abstract: A controller (70) controls the boost pressure of an internal combustion engine (60) comprising two intake/exhaust units, each intake/exhaust unit comprising a turbocharger (10) which supercharges intake air in an intake passage (20) using exhaust energy in an exhaust passage (30), and an exhaust gas recirculating device (40, 41) which recirculates a part of the exhaust gas in the exhaust passage to the intake passage. The controller (70) calculates an opening difference between valves in the two units (S121), and controls a regulating device (13) in each of the two units on the basis of this opening difference (S123-S125). As a result, the boost pressures of the turbochargers (10) match, and hence an equal amount of NOx can be discharged from each exhaust passage (30), and the NOx can be purified favorably by a catalyst.

Abstract: An engine control system is configured to improve the estimation accuracy of a fresh intake air quantity and a total intake air quantity that flows into the combustion chambers. The engine control system is configured to estimate an estimated EGR rate value Regr using a primary lag process for a target EGR rate, calculate a volumetric efficiency equivalency value based on the estimated EGR rate value Regr, estimate an estimated fresh intake air value Qac that flows into the combustion chamber based on a rate of change in a volumetric efficiency equivalency value Kin/Kinn-1 of the estimated EGR rate value Regr and the volumetric efficiency equivalency value Kin, and estimate an estimated total intake air quantity value Qsco2 that includes the EGR gas based on the estimated fresh intake air value Qac and the estimated EGR rate value Regr.

Abstract: A controller (70) controls the boost pressure of an internal combustion engine (60) comprising two intake/exhaust units, each intake/exhaust unit comprising a turbocharger (10) which supercharges intake air in an intake passage (20) using exhaust energy in an exhaust passage (30), and an exhaust gas recirculating device (40, 41) which recirculates a part of the exhaust gas in the exhaust passage to the intake passage. The controller (70) calculates an opening difference between valves in the two units (S121), and controls a regulating device (13) in each of the two units on the basis of this opening difference (S123-S125). As a result, the boost pressures of the turbochargers (10) match, and hence an equal amount of NOx can be discharged from each exhaust passage (30), and the NOx can be purified favorably by a catalyst.

Abstract: A particulate deposit amount Spm on a particulate filter disposed in an exhaust passage is estimated during a usual period different from a regeneration period of the particulate filter and during the regeneration period thereof respectively. An increase value Dpm per unit time of the Spm during the usual period is estimated based upon an engine operating condition and a total amount of the Spm is determined by integration thereof (S15, 16). On the other hand, a particulate deposit amount Spm decreasing by burning during the regeneration period is determined by, one by one, subtracting a decrease value Dpm per unit time estimated based upon a particulate deposit amount Spmi that is determined by the above integration at a starting point of the regeneration period from the Spmi (S12, 17).

Abstract: A diesel particulate filter 14 that traps particulate matters in an exhaust gas and a NOx trap catalyst 13 that traps NOx in the exhaust gas are disposed in an exhaust passage (10) in an internal combustion engine (1). When a regeneration timing of the diesel particulate filter (14) and one of a regeneration timing of SOx and a regeneration timing of NOx are overlapped, the diesel particulate filter regeneration is carried out first and thereafter, the SOx regeneration or the NOx regeneration is carried out.

Abstract: A vehicle system controls a compression ignition internal combustion engine equipped with a supercharger system including a plurality of superchargers. The compression ignition internal combustion engine has an exhaust gas recirculation (EGR) system. The vehicle system determines a desired intake manifold supercharging state (tQac) and a desired EGR rate (Megr). The vehicle system includes control logics, each having a first input parameter and a second input parameter, for determining desired set points (Rvnt1 & Rvnt2) for the plurality of superchargers, respectively. The desired set points are used to control the plurality of superchargers, respectively. The vehicle system also includes control logic for determining the first input parameters in response to the desired intake manifold supercharging state. The vehicle system further includes control logic for determining the second input parameters in response to the desired EGR rate.

Abstract: An engine control system is configured to improve the estimation accuracy of a fresh intake air quantity and a total intake air quantity that flows into the combustion chambers. The engine control system is configured to estimate an estimated EGR rate value Regr using a primary lag process for a target EGR rate, calculate a volumetric efficiency equivalency value based on the estimated EGR rate value Regr, estimate an estimated fresh intake air value Qac that flows into the combustion chamber based on a rate of change in a volumetric efficiency equivalency value Kin/Kinn-1 of the estimated EGR rate value Regr and the volumetric efficiency equivalency value Kin, and estimate an estimated total intake air quantity value Qsco2 that includes the EGR gas based on the estimated fresh intake air value Qac and the estimated EGR rate value Regr.

Abstract: A control unit (41) controls an opening of an exhaust recirculation valve (6) according to a running condition of a diesel engine (1). The control unit (41) calculates an equivalence ratio of the gas mixture supplied to the engine (1) and a target intake fresh air amount taking account of the air amount in the exhaust gas recirculated by the exhaust gas circulation valve (6), based on the opening of the valve (6) and a target excess air factor of the engine (1) set according to the running condition. By controlling a turbocharger (50) according to the target intake fresh air amount, and by controlling the fuel supply mechanism according to a fuel injection amount calculated from the equivalence ratio, the excess air factor of the engine (1) and an exhaust gas recirculation rate of the exhaust gas recirculation valve (6) are respectively controlled to optimum values.

Abstract: In air-fuel ratio control apparatus and method for an internal combustion engine having an EGR valve interposed in an EGR passage between an intake manifold and an exhaust manifold, a target EGR quantity is calculated, a determination is made which of air-fuel ratio feedback controls through an EGR control and through an intake-air quantity is to be executed according to the target EGR quantity, and one of the air-fuel ratio feedback controls is selectively made according to a result of a determination of which of the air-fuel feedback controls is to be executed. During an execution of a rich spike control, the feedback control through the intake-air quantity control is unconditionally executed.

Abstract: A basic target excess air factor tLAMBDA0 and a target fresh air intake amount tQac are set base upon the operation condition of an engine (30). A target excess air factor tLAMBDA is calculated by multiplying the ratio of a real fresh air intake amount rQac as detected by a sensor (16) and the target fresh air intake amount tQac by the basic target excess air factor tLAMBDA0. A fuel injector (9) is controlled so that the amount of fuel injected thereby converges to a target fuel injection amount tQf which corresponds to the target excess air factor tLAMBDA. It is possible to prevent variation of the output torque of the engine (30) accompanying a rich spike by this control, even if the basic target excess air factor tLAMBDA0 varies abruptly, since the fuel injection amount varies in correspondence to the variation of the real fresh air intake amount rQac.