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.

A first switch designates one of energization instruction signals to designate a valve closing detection cylinder. A valve closing detection unit monitors downstream voltages of the fuel injection valves to detect occurrence of an inflection point in change of the downstream voltages and detects valve closing. A second switch designates one of the downstream voltages and designates the valve closing detection cylinder. A stage number designation unit designates a valve closing detection stage number. A valve closing time measuring unit measures a valve closing time, which is from a switching timing at which the energization instruction signal is switched from ON to OFF to a valve closing detection timing of the valve closing, for injection of the valve closing detection stage number of the valve closing detection cylinder. A valve closing time learning unit learns the valve closing time measured by the valve closing time measuring unit.

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.

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 purpose of the present invention is to provide a control means which, with respect to injection control of a fuel injection valve, reduces deviation between an injection quantity of fuel injected by the fuel injection valve and a target value, the deviation being caused due to a pressure in a combustion chamber, as an injection timing in a compression stroke of an engine is retarded. The present invention pertains to a fuel injection valve that performs a plurality of injections in one engine cycle, and performs control in such a manner that injection pulse signals and are transmitted to a drive circuit, and from the drive circuit for the fuel injection valve that outputs drive current waveforms for fuel injection, the injection pulse signal in the compression stroke when the injection timing is retarded is shortened.

An intake stroke injection and a compression stroke injection are performed during catalyst warm-up control (upper section in FIG. 7). During the catalyst warm-up control, a discharge period at an electrode portion is set on a retard side of compression top dead center, and an expansion stroke injection is performed during the discharge period. However, when a distance between a spray contour surface and the electrode portion increases, an additional injection (first injection) is performed in advance of the expansion stroke injection (second injection) (lower section in FIG. 7). The additional injection is performed at a timing that is on the retard side of compression top dead center and is on an advance side relative to a start timing of the discharge at the electrode portion.

A control device is configured to perform, when it is estimated that a combustion fluctuation increases, estimation related to an ignition delay for initial flame generated from a discharge spark and an air-fuel mixture containing fuel spray injected by intake stroke injection. When it is estimated that the ignition delay for the initial flame is increased from that before the increase in the combustion fluctuation, an injection amount in expansion stroke injection is reduced in a next time cycle. When it is estimated that the ignition delay for the initial flame is reduced from that before the increase in the combustion fluctuation, the injection amount in expansion stroke injection is increased in a next time cycle.

An internal combustion engine and a method of controlling an internal combustion engine are provided, that are more efficient than existing engines. The internal combustion engine includes a combustion chamber, and the engine is configurable to operate in: a compressionless operating mode where the engine is driven by combustion of fuel and oxidant in the combustion chamber without compression of the fuel and oxidant; and a compression generating operating mode where the engine is used to compress fluid in the combustion chamber.

A method for operating a combustion engine performing an injection quantity correction is described. A total injection quantity per pulse of an injector is divided into a plurality of smaller equal quantity pulses. The smaller quantity pulses are implemented in ballistic injector mode. On the basis of this step, a corresponding offset correction is carried out. After the offset correction has been applied, a further correction is carried out in linear injector mode. An additional alternative for performing an injection quantity correction without additional sensor hardware is thereby provided.