When switching the combustion mode from a stoichiometric mode to a homogeneous lean mode, a controller starts switching of the combustion mode after switching of the opening angle of a tumble control valve is started. When a target operating point of an internal combustion engine lies outside a predetermined operational region that is set in a range that excludes at least a low intake load factor region and includes at least a medium intake load factor and medium engine speed region, the controller sets the waiting time from the start of switching of the opening angle of the tumble control valve to the start of switching of the combustion mode to be longer than when the target operating point lies in the predetermined operational region.

An object is to supply fresh air and EGR gas into a cylinder in good balance according to the required load in a naturally aspirated gasoline engine. When the operation state of the engine falls in a low load range, a control apparatus adjusts the degree of opening of the second throttle while keeping the first throttle fully open and controls EGR gas quantity by adjusting the degree of opening of the EGR valve. When the operation state falls in a middle load range, the apparatus controls EGR gas quantity by adjusting the degree of opening of the first throttle while keeping the EGR valve fully open. When the operation state falls in a high load range, the apparatus adjusts the degree of opening of the first throttle while keeping the second throttle fully open and controls EGR gas quantity by adjusting the degree of opening of the EGR valve.

Various methods and systems are provided for a multi-fuel capable engine. In one example, a system comprises an engine having at least one cylinder controlled via an intake valve, a first fuel system to deliver liquid fuel and a second fuel system to deliver gaseous fuel to the at least one cylinder, a variable valve timing actuation system to adjust one or more of an opening or a closing timing of the intake valve, and a controller. The controller is configured to, during a liquid fuel only mode, adjust the variable valve timing actuation system to close the intake valve at a first timing based at least on engine load, and during a multi-fuel mode, adjust the variable valve timing actuation system to close the intake valve at a second timing.

Main fuel injected from the fuel injector into the combustion chamber is made to auto-ignite. During the compression stroke after injection of the main fuel and before the auto-ignition of the main fuel, first auxiliary fuel and second auxiliary fuel are successively injected from the fuel injector. By controlling the injection timing of the first auxiliary fuel, the ignition timing of the spark plug, and the injection timing of the second auxiliary fuel, the first auxiliary fuel is made to burn by flame propagation combustion by the ignition action of the spark plug, the second auxiliary fuel is made to be injected inside the flame propagation combustion region, and the second auxiliary fuel is made to burn by diffusive combustion before auto-ignition of the main fuel occurs.

The invention relates to a method for operating an internal combustion engine comprising: determining a first set point value of a volume of air to be taken into the combustion chamber of the internal combustion engine within one working cycle thereof by retrieving the first set point value from a first characteristic map stored in a memory device of an electronic computing device as a function of a current engine speed of the internal combustion engine and as a function of a torque to be provided by the internal combustion engine; and determining a second set point value by retrieving the second set point value from a second characteristic map stored in the memory device of the electronic computing device as a function of a current engine speed of the internal combustion engine and as a function of a current volume of air supplied to the combustion chamber.

A prime mover control device of a work vehicle equipped with a torque converter includes: a speed ratio calculation unit that calculates a speed ratio of the torque converter; and a rotational speed limit unit that, when a speed ratio falls within a preset speed ratio range, limits a maximum rotational speed of the prime mover to be lower as compared with a maximum rotational speed set when a speed ratio falls without the preset speed ratio range. When a state in which the speed ratio calculated by the speed ratio calculation unit falls within the preset speed ratio range is maintained for a predetermined time period, the rotational speed limit unit changes a maximum rotational speed of the prime mover to a higher maximum rotational speed than the limited maximum rotational speed limited to be lower by the rotational speed limit unit.

Provided is a hybrid work machine in which a hybrid system and a downsized engine are used. The hybrid work machine improves fuel consumption, improves exhaust characteristics, and reduces noise. The hybrid work machine also performs rapid charging of a power storage device while preventing decreases in the output power of a hydraulic pump if the charge amount of the power storage device is extremely insufficient. A vehicle body controller 46 performs engine revolution speed decreasing control in which, if the charge rate of a battery 33 becomes equal to or less than a minimum charge rate, the target revolution speed of an engine 11 is reduced. The vehicle body controller also performs torque reducing control in which the maximum absorption torque of a hydraulic pump 21 is reduced. By performing these control operations, the vehicle body controller coercively generates surplus torque for the engine and operates a generator-motor 31 as a generator with the use of the surplus torque, thereby rapidly charging the battery.

A method of controlling CDA conversion may include determining whether CDA device is in CDA mode driving area according to obtained vehicle operation status signal; preparing, when CDA device is in CDA mode driving area, for operating in the CDA driving mode; performing conversion to CDA mode on each cylinder of the CDA device; and controlling, when CDA device is not in DA mode driving area, vehicle driving according to normal area operation map of the CDA device, wherein at performing of conversion to CDA mode on each cylinder, when converting mode of the CDA device from on-operation mode to an operation mode, after combustion is performed in selected cylinder, first exhaust valve maintains an operation state, and remaining exhaust valves and intake valves are converted to non-operation state to perform an exhaust anti-trap control.

An ECU avoids engine stall by putting a compressor into a stationary state in a case where the rotation speed of a crankshaft is equal to or less than a predetermined speed during an idle operation of an internal combustion engine. During the idle operation, the ECU calculates a total load torque applied to the crankshaft by the compressor and an alternator. The ECU calculates the maximum torque of the internal combustion engine during the idle operation based on a target speed during the idle operation. Then, the ECU raises the predetermined speed in a case where the value obtained by subtracting the load torque from the maximum torque is equal to or less than a predetermined value.

Aspects of the present disclosure are directed to controlling an inner effective torque or an effective torque of a drive unit via a unit controlling unit. In some embodiments, the control method may include providing desired values for the inner effective torque or the effective torque and determining actual values for the inner effective torque or the effective torque during operation of the drive unit on a test stand, and in that actuating dynamics of the drive unit are taken into account in the control by means of a transfer function by correcting the desired values of the control with the transfer function or in that for controlling the inner effective torque or the effective torque of the drive unit, a feed forward control of a manipulated variable of the drive unit is used.