Abstract: An engine includes a first injection valve, which is one of port and direct injection valves, and a second injection valve, which is the other. When operating only the first injection valve based on a base injection amount, which has been corrected using a feedback operation amount and a first learning value, an air-fuel ratio control apparatus updates the first learning value and determines that the first learning value has converged on condition that a correction ratio of the base injection amount is not more than a predetermined ratio. When the first and second injection valves are being operated, the apparatus updates a second learning value for the second injection valve on condition that the first learning value has converged and the ratio of the injection amount of the second injection valve is not less than a specified value.

Abstract: An air-fuel ratio controller of an internal combustion engine includes an open-loop processor setting a base injection amount, a feedback processor calculating a feedback operation amount, an increase processor performing an increase correction on the base injection amount when a temperature of the internal combustion engine is a specified temperature or lower, an operation processor operating a fuel injection valve based on the corrected base injection amount and that is corrected using the feedback operation amount and a learning value, and an update processor updating the learning value. If the increase processor performs the increase correction, the update processor updates the learning value to increase an increase correction rate of the base injection amount when a temperature of the cylinder wall surface is high.

Abstract: A control system of an internal combustion engine includes an electronic control unit. The electronic control unit is configured to: (i) obtain a detection value of a fuel pressure sensor at fixed sampling time intervals; (ii) calculate a center fuel pressure value of a pulsation of the fuel pressure, based on at least a first latest fuel pressure value and a second latest fuel pressure value as detection values of the fuel pressure sensor, (iii) calculate an amplitude of the pulsation of the fuel pressure, based on at least the second latest fuel pressure value and the first latest fuel pressure value; (iv) calculate an initial phase of the pulsation of the fuel pressure, based on at least one of the second latest fuel pressure value and the first latest fuel pressure value, and (v) predict a fuel pressure value corresponding to the crank angle, based on a predetermined formula.

Abstract: A control device for an internal combustion engine is equipped with an electronic control unit. The electronic control unit is configured to: i) calculate amplitudes of respective waves, respectively, originating from a plurality of factors that causes fuel pressure pulsation within a low-pressure fuel passage, vibration frequencies of the respective waves within a crank angle range of 360 degrees, initial phases of the respective waves, and central fuel pressure values of the respective waves; and ii) predict a fuel pressure value at an arbitrary crank angle according to a model formula showing a synthesized wave obtained by synthesizing the respective waves, on a basis of the amplitudes, the vibration frequencies, the initial phases, and the central fuel pressure values of the respective waves calculated.

Abstract: A control system of an internal combustion engine includes a port injection valve and an electronic control unit. The electronic control unit is configured to: (i) obtain one of a start crank angle and an end crank angle, (ii) calculate the other of the start crank angle and the end crank angle, based on an equation for calculating a provisional injection amount of the case where the port injection valve provisionally injects the fuel with the one of the start crank angle and the end crank angle and a given crank angle range; (iii) convert a crank angle range from the start crank angle to the end crank angle, into a target energization period; and (iv) perform fuel injection by energizing the port injection valve for the target energization period.

Abstract: A control device for an internal combustion engine capable of performing additional injection in addition to regular injection includes an electronic control unit. The electronic control unit is configured to calculate an ignition timing at a predetermined crank angle before a compression top dead center. The electronic control unit is configured to calculate an injection amount of fuel at a predetermined time interval and to calculate an injection amount of the fuel at the predetermined crank angle. The electronic control unit is configured to control the fuel injection valve such that the fuel injection valve additionally injects the fuel in an increase amount before ignition, when the injection amount calculated at the predetermined crank angle is increased due to retardation of the ignition tinting calculated after the fuel in the injection amount calculated at the predetermined time interval is regularly injected.

Abstract: A drive system for fuel injection valves includes a battery, a capacitor, a drive control unit and an electronic control unit. The electronic control unit is configured to, when an energization start interval between a start of energization of a last one of the fuel injection valves and a start of energization of a current one of the fuel injection valves is longer than or equal to a peak reaching time of a last one of the fuel injection valves, extend an energization time of the current one of the fuel injection valves as the energization start interval reduces. The electronic control unit is configured to, when the energization start interval is shorter than the peak reaching time, reduce the energization time of the current one of the fuel injection valves is energized as the energization start interval reduces.

Abstract: An electronic control unit for an internal combustion engine configured to achieve demands concerning various kinds of functions of an internal combustion engine by coordinative control of a plurality of actuators concerning an operation of the internal combustion engine. The electronic control unit of the internal combustion engine is provided with a demand generation r level, a physical quantity mediation level, a controlled variable setting level, and a controlled variable mediation level. The controlled variable mediation level is provided just below the controlled variable setting level and includes a fundamental injection control mediation portion which mediates demand variables transmitted from the demand generation level not through the physical quantity mediation level and mediates controlled variables of the injections during a driving of the engine and a startup injection control mediation portion which mediates an, injection controlled variable upon startup.

Abstract: An electronic control unit of the present invention includes: a demand generation level that generates and outputs a demand value concerning various kinds of functions; a physical quantity mediation level that aggregates and mediates the demand value for each predetermined physical quantity; and a controlled variable setting level that sets a controlled variable of the actuator based on the mediated demand value and transmits a signal in a single direction from a higher level to a lower level. A controlled variable mediation level that aggregates and mediates demand values expressed with controlled variables of the actuators set on the controlled variable setting level and a demand value transmitted from the demand generation level not through the physical quantity mediation level, together with demand values mediated by the physical quantity mediation level is provided below the controlled variable setting level.

Abstract: The engine ECU executes a program including the step of setting an upper limit guard value of a fuel pressure by executing low fuel pressure control in the case where a low fuel pressure control execution condition is satisfied with fulfillment of conditions that execution of the low fuel pressure control is permitted, that engine speed NE is lower than a threshold value, and that the atmospheric pressure is higher than a threshold value, and the step of controlling the fuel pressure to be a target fuel pressure within a range not exceeding the upper limit guard value.

Abstract: To quickly suppress a detected decrease in engine speed in a direct injection internal combustion engine (10), a fuel injection quantity is increased by performing a supplementary fuel injection in addition to a normal fuel injection.

Abstract: In a direct injection internal combustion engine which switches a fuel injection mode between a batch injection in which fuel is injected once and a split injection in which fuel is injected at a plurality of timings, a fuel increase amount is set larger for the split injection than for the batch injection when increase-correcting a fuel injection quantity set based on an engine operating state.

Abstract: The engine ECU executes a program including the step (S320) of setting an upper limit guard value of a fuel pressure by executing low fuel pressure control in the case where a low fuel pressure control execution condition is satisfied with fulfillment of conditions that execution of the low fuel pressure control is permitted, that engine speed NE is lower than a threshold value, and that the atmospheric pressure is higher than a threshold value (S310), and the step (S330) of controlling the fuel pressure to be a target fuel pressure within a range not exceeding the upper limit guard value.

Abstract: A valve characteristic control apparatus is provided in an internal combustion engine including a variable valve mechanism that can change at the least, among valve characteristics of an exhaust valve, a closing timing of the exhaust valve, and in which a number of injections of fuel is changed during one engine cycle. The valve characteristic control apparatus sets the closing timing of the exhaust valve to a retard side during an engine warming up operation. When setting to the retard side is performed, if two injections are performed, an exhaust side target displacement angle VTTex of the exhaust valve is calculated based on a dual injection use map. On the other hand, if one injection is performed, the exhaust side target displacement angle VTTex of the exhaust valve is calculated based on a single injection use map.

Abstract: A valve characteristic control apparatus is provided in an internal combustion engine including a variable valve mechanism that can change at the least, among valve characteristics of an exhaust valve, a closing timing of the exhaust valve, and in which a number of injections of fuel is changed during one engine cycle. The valve characteristic control apparatus sets the closing timing of the exhaust valve to a retard side during an engine warming up operation. When setting to the retard side is performed, if two injections are performed, an exhaust side target displacement angle VTTex of the exhaust valve is calculated based on a dual injection use map. On the other hand, if one injection is performed, the exhaust side target displacement angle VTTex of the exhaust valve is calculated based on a single injection use map.

Abstract: An engine ECU executes a program including: the step of outputting a fuel-cut instruction when conditions that an accelerator position PA is not higher than a threshold value and a rate of increase DNE of engine speed NE is not lower than a determination value DNE(0) are satisfied; the step of fully closing throttle opening; and the step of suspending ignition of air-fuel mixture by a spark plug.

Abstract: To quickly suppress a detected decrease in engine speed in a direct injection internal combustion engine (10), a fuel injection quantity is increased by performing a supplementary fuel injection in addition to a normal fuel injection.

Abstract: In a direct injection internal combustion engine (10) which switches a fuel injection mode between a batch injection in which fuel is injected once and a split injection in which fuel is injected at a plurality of timings, a fuel increase amount is set larger for the split injection than for the batch injection when increase-correcting a fuel injection quantity set based on an engine operating state.

Abstract: An internal combustion engine has a fuel injection valve. To cause an actual air-fuel ratio of air-fuel mixture burned in the engine to be equal to a target value, an electronic control device corrects a fuel injection amount from the fuel injection valve using a feedback correction value. The feedback correction value is changed based on the actual air-fuel ratio. The electronic control device computes, as a safeguard value, a value of the feedback correction value that causes a fuel injection time, which is an instruction sent to the fuel injection valve, to be a permissible minimum time. When the fuel injection time is less than the permissible minimum time, the electronic control device limits the lowest value of the feedback correction value to the safeguard value. As a result, the actual air-fuel ratio is prevented from being rich.

Abstract: A requested injection amount of fuel necessary during ignition cut-off at the time of start at an extremely low temperature is calculated (step ST2), injection start timing and injection end timing between which wetting of a spark plug by fuel is less likely are set (step ST3), and the number of times of ignition cut-off is calculated based on the injection start timing and the injection end timing and the requested injection amount (step ST4). The injection start timing and the injection end timing are thus restricted to timings between which plug wetting is less likely, and the number of times of ignition cut-off is calculated based on the injection start timing and the injection end timing and the requested injection amount, so that wetting of the spark plug by fuel at the extremely low temperature can be avoided even in an in-cylinder direct-injection engine.