A combustion system is applied to an engine. The combustion system includes an injection device that injects a fuel into a combustion chamber, a spark plug that ignites fuel in the combustion chamber, and a control device that controls the injection device and the spark plug. The control device includes a first control unit that executes predetermined first control. In the first control, control is performed such that, a total injection amount corresponding to all the fuel injected by the injection device in one combustion cycle of the engine is injected within a first period corresponding to a period from valve close timing which brings an intake valve into a closed state until a first half of a compression stroke of the engine ends.

An air-assisted jet flame ignition device includes a housing, a fuel-air premixing unit, and a prechamber. The fuel-air premixing unit includes a fuel injector, an air injection valve, a premixing sleeve, a premixing sleeve inner core placed in the premixing sleeve, and a fuel injector fastening bolt. An inner wall surface of the premixing sleeve and an outer wall surface of the premixing sleeve inner core form a premixing sleeve inner cavity. An inner wall surface of the premixing sleeve inner core, a lower end surface of a nozzle of the fuel injector, and an upper end surface of an air inlet of the air injection valve form a premixing cavity. The premixing cavity coupled to the premixing sleeve inner cavity via a through hole on the sidewall of the premixing sleeve inner core. A prechamber nozzle is fixedly coupled to the lower part of the housing.

A variety of methods and arrangements for reducing noise, vibration and harshness (NVH) in a skip fire engine control system are described. In one aspect, a firing sequence is used to operate the engine in a skip fire manner. A smoothing torque is determined that is applied to a powertrain by an energy storage/release device. The smoothing torque is arranged to at least partially cancel out variation in torque generated by the skip fire firing sequence. Various methods, powertrain controllers, arrangements and computer software related to the above operations are also described.

An ignition assembly configuration in piston engine with a main piston and an auxiliary piston, the ignition assembly is mounted on the cylinder wall and connects to the combustion chamber; the ignition assembly comprises an connection cut-out passage, an ignition device, or ignition device combined with a fuel injection nozzle, or an ignition device combined with a fuel injection nozzle and a pressure sensor passage. Wherein the auxiliary piston has a by-pass passage to keep the ignition assembly connected to the combustion chamber when the auxiliary piston moves down below the uppermost position of the main piston and blocks the ignition assembly cut-out passage; wherein the uppermost position of the ignition assembly is at or aligned with the uppermost position of the auxiliary piston in combustion stroke, the lowermost position of the ignition assembly is at or aligned with the uppermost position of the main piston. Fuel-water injection, multiple fuel injections and combustions can be easily practiced in the new configuration.

A controller for an internal combustion engine is configured to control the fuel injection valve so that the fuel injection valve selectively performs partial lift injection, which does not open a valve member at a fully open position, and full lift injection, which opens the valve member at the fully open position. The internal combustion engine includes the fuel injection valve and a fuel supply system. The controller includes an energizing time setting unit, a fuel pressure calculation unit, and a smoothening process unit. The energizing time setting unit is configured to set an energizing time for the full lift injection based on graded fuel pressure calculated by the smoothening process unit and set an energizing time for the partial lift injection based on fuel pressure calculated by the fuel pressure calculation unit.

A method for starting an internal combustion engine comprises the steps of: providing an internal combustion engine having at least one cylinder and a piston supported at a crankshaft for repeated reciprocal movement in the cylinder so as to define a main combustion chamber, the internal combustion engine further having an ignition device arranged in said cylinder with an igniter portion and a fuel injector which are both arranged at a pre-chamber, wherein the pre-chamber has a plurality of orifices for providing fluid communication between said pre-chamber and the main combustion chamber, injecting fuel in the pre-chamber, and igniting the injected fuel in the pre-chamber for pre-heating of the pre-chamber prior to injecting fuel in the main combustion chamber for combusting the injected fuel in the main combustion chamber.

A fuel injection valve control device controlling a fuel injection valve that injects a fuel into a combustion chamber includes an operation-condition calculation portion that calculates a fuel injection condition of the fuel injection valve based on a crank angle detected by a crank angle sensor that detects the crank angle of an engine, a current-waveform setting portion that sets a current waveform of a current supplied to the fuel injection valve on the basis of the fuel injection condition calculated by the operation-condition calculation portion, and so on. The current-waveform setting portion sets the current waveform so as to set a temporal change of a pickup current of a needle provided in the fuel injection valve to be equal to or less than a predetermined reference value when a fuel injection start timing is equal to or more than 180 degrees BTDC. The current-waveform setting portion sets the current waveform so as to set a temporal change of the pickup current of the needle to be more than the predetermined reference value when the fuel injection start timing is smaller than 180 degrees BTDC.

A fuel injection valve control device controlling a fuel injection valve that injects a fuel into a combustion chamber includes an operation-condition calculation portion that calculates a fuel injection condition of the fuel injection valve based on a crank angle detected by a crank angle sensor that detects the crank angle of an engine, a current-waveform setting portion that sets a current waveform of a current supplied to the fuel injection valve on the basis of the fuel injection condition calculated by the operation-condition calculation portion, and so on. The current-waveform setting portion sets the current waveform so as to set a temporal change of a pickup current of a needle provided in the fuel injection valve to be equal to or less than a predetermined reference value when a fuel injection start timing is equal to or more than 180 degrees BTDC. The current-waveform setting portion sets the current waveform so as to set a temporal change of the pickup current of the needle to be more than the predetermined reference value when the fuel injection start timing is smaller than 180 degrees BTDC.

The present invention determines whether multi-stage injection control is operating normally or abnormally, and carries out a failsafe of multi-stage injection control as necessary. The present invention, which solves the problem described above, has means such as the following. The invention is provided with fuel injection valves provided respectively to each cylinder, an opened/closed valve detection means for detecting either one or both of an open valve state and a closed valve state of the fuel injection valves on the basis of the drive currents or drive voltages of the fuel injection valves, and a detection execution determination means for determining a detection execution time period including the detection start timing and the detection end timing of the open valve state or closed valve state; detection interference such as overlapping detection with another cylinder and overlapping of open valve detection and closed valve detection being preventable, and risks such as erroneous detection being reducible.

The present invention determines whether multi-stage injection control is operating normally or abnormally, and carries out a failsafe of multi-stage injection control as necessary. The present invention, which solves the problem described above, has means such as the following. The invention is provided with fuel injection valves provided respectively to each cylinder, an opened/closed valve detection means for detecting either one or both of an open valve state and a closed valve state of the fuel injection valves on the basis of the drive currents or drive voltages of the fuel injection valves, and a detection execution determination means for determining a detection execution time period including the detection start timing and the detection end timing of the open valve state or closed valve state; detection interference such as overlapping detection with another cylinder and overlapping of open valve detection and closed valve detection being preventable, and risks such as erroneous detection being reducible.