A control device for an internal combustion engine is programmed, during a catalyst warm-up control, to perform first fuel injection by an injector in an intake stroke, control an ignition device so as to generate a discharge spark in a predetermined period in an expansion stroke, and perform second fuel injection, at a timing retarded from a compression top dead center, such that its injection period overlaps with at least a part of the predetermined period and an end timing of the injection period is advanced from an end timing of the predetermined period. Further, the control device is programmed, during the catalyst warm-up control, to control an actual tumble ratio depending on a result of determination using a first index value representing a speed of initial combustion accompanying an ignition by the ignition device and a second index value representing a speed of main combustion accompanying the ignition.

An ignition coil control system may include first and second ignition coils, and a spark plug including a pair of electrodes in which generates spark discharge by discharge currents of the first ignition coil and the second ignition coil, a DC-DC converter connected to a primary coil of the first ignition coil, a primary coil of the second ignition coil and a battery; in which converts current magnitude supplied to a primary coil of the first ignition coil and a primary coil of the second ignition coil from a battery, and a controller in which controls the spark discharge of the electrodes by adjusting an amount and a duration of the discharge current of the first ignition coil and the second ignition coil base on a pulse signal, wherein the controller is configured to selectively execute a multi-state ignition through the first ignition coil and the second ignition coil and a single-stage ignition through one of the first ignition coil and the second ignition coil according to an operation region of an engine.

An electronic control unit of an internal combustion engine is configured to control the fuel injection valve and to control a spark plug if necessary such that fuel is combusted by pre-mixture compression ignition combustion or flame propagation combustion. The electronic control unit is configured to perform homogeneous combustion in a flame ignition operation range when switching failure has not occurred, the homogeneous combustion being combustion in which fuel homogeneously diffused into the combustion chamber is ignited using the spark plug and is combusted by flame propagation combustion. The electronic control unit is configured to perform spray-guided stratified combustion in a second operation range when the switching failure has occurred, the spray-guided stratified combustion being combustion in which fuel in the fuel injection path is ignited using the spark plug and is combusted by the flame propagation combustion.

A fuel property determination apparatus for an internal combustion engine is applied to an internal combustion engine that is equipped with an ignition plug and an ignition timing controller. An electronic control unit provided in the fuel property determination apparatus executes a determination process of making a determination on a property of a fuel supplied to the internal combustion engine based on an ignition sufficiency ratio, during a predetermined period after startup of the internal combustion engine. The electronic control unit is configured to determine that the property of the fuel is heavy when a determination index value that is obtained by subjecting the ignition sufficiency ratio to a smoothing process is equal to or larger than a predetermined threshold. The electronic control unit is configured to set a smoothing coefficient to a value corresponding to each of a first period, a second period, and a third period.

An object is to achieve stable diesel combustion and improvement in the thermal efficiency of the diesel combustion in an internal combustion engine using a fuel having a relatively high self-ignition temperature. A control apparatus for an internal combustion engine includes a fuel injection valve capable of injecting fuel into a combustion chamber and an ignition device whose position relative to the fuel injection valve is set in such a way that it can ignite fuel spray directly. The apparatus performs pre-injection at a predetermined pre-injection time during the compression stroke and main injection at a predetermined injection start time after pre-spray formed by the pre-injection is ignited by the ignition device, thereby causing self-ignition to occur and causing at least a portion of the main-injected fuel to burn by diffusion combustion. When the quantity of the pre-injected fuel is increased, the pre-injection time is advanced responsive to the increase in the quantity of the pre-injected fuel.

A small-size injector having a built-in ignition device which can surely inject fuel and ignite the fuel with low electric power by the ignition device with a simple configuration is provided. The injector comprises a fuel injecting device 2 having a fuel injecting port 20 that injects the fuel, an ignition device 3 configured to ignite the injected fuel, and a casing 10 inside housing therein the fuel injecting device 2 and the ignition device 3 together. The motion device 3 is constituted of a plasma generator 3 which integrally comprises a booster 5 having a resonation structure capacity-coupled with an electromagnetic wave oscillator MW configured to oscillate an electromagnetic wave, and a discharger 6 configured to cause a discharge of a high voltage generated by the booster 5.

The object is to provide an injector with a built-in ignition device that can achieve downsize of device as a whole without changing significantly the structure of a fuel injection device. The injector with the built-in ignition device comprises an ignition device 3 and a fuel injection device 2. In the ignition device 3, an electromagnetic wave oscillated from an electromagnetic wave oscillator MW is boosted by a booster that is constituted by a resonance structure, a potential difference between a ground electrode 51 and a discharge electrode 31 is increased, and a discharge is caused. In the fuel injection device 2, a valve body part of a nozzle needle 24 is moved toward or away from a valve seat (orifis) 23a, and thereby, the fuel injection control is performed. Then, the resonance structure is formed by a dielectric member 30 that is connected to the electromagnetic wave oscillator and formed on the surface of a fuel injection pipe 21, and an inner wall surface 50a of a mounting port 50 for an injector of a cylinder head 5. A discharge electrode 31 is a projection that is formed on the surface of the fuel injection pipe 21, and a discharge is caused by making a position of the wall surface of the mounting port 5 that is closest to the discharge electrode 31 as a ground electrode 51.

A small-size injector having a built-in ignition device which can surely inject fuel and ignite the fuel with low electric power by the ignition device with a simple configuration is provided. The injector comprises a fuel injecting device 2 provided with a fuel injecting port 20 configured to inject the fuel, an ignition device 3 configured to ignite the injected fuel, and a casing 10 inside housing therein the fuel injecting device 2 and the ignition device 3 together. The ignition device 3 is constituted of a plasma generator 3 which integrally comprises a booster 5 having a resonation structure capacity-coupled with an electromagnetic wave oscillator MW configured to oscillate an electromagnetic wave, and a discharger 6 configured to cause a discharge of a high voltage generated by the booster 5.

An injector unit that can use a gaseous fuel such as CNG in an already-existing diesel engine and a spark plug that uses the injector unit, are provided. The injector unit includes an injector, an igniter having a resonance structure configured to boost an inputted microwave and a discharger configured to perform a discharge, and a casing configured to house therein the injector and the igniter. The igniter includes a first part configured to transmit the inputted microwave, a second part configured to perform a capacity coupling to attain an impedance matching between the microwave and the igniter, and a third part configured to transmit the capacity-coupled microwave to the discharger. Moreover, the igniter is bent at a boundary of the first part and the second part, a boundary of the second part and the third part, or inside the first part.

An internal combustion engine includes a spark plug which protrudes into a combustion chamber. The spark plug has a central electrode and a ground electrode, and is configured such that a spark is generated between the central electrode and the ground electrode by electrical discharge. The spark plug has a vortex generator that separates an air flow near the ground electrode from the ground electrode and generates a vortex at a downstream side. The central electrode and the ground electrode are placed in a manner such that a spark or a flame deformed by an air flow flowing between the central electrode and the ground electrode enters the trailing vortex, or the spark penetrates through the inside of the trailing vortex.