Internal combustion engine comprising at least one cylinder and a piston supported for repeated reciprocal movement in the cylinder so as to define a combustion chamber of an engine bore diameter A-A, the internal combustion engine further comprising an ignition device arranged in said cylinder having an igniter portion and an fuel injector which are both arranged in a pre-chamber, wherein the pre-chamber comprises a plurality of orifices for providing fluid communication between said pre-chamber and the combustion chamber, and wherein the plurality of orifices are of an overall orifice area so that the ratio between the overall orifice area and the engine bore diameter A-A ranges from 0.01 mm to 0.2 mm.

An apparatus and method are disclosed for an injector assembly including an injector tip having a prechamber, such as a permanent, passive prechamber (PPPC), and a nozzle combustion shield (NCS) to mitigate pre-ignition events, such as knocking, caused by overheating of the prechamber. The NCS has a thermal conductivity greater than the injector tip. The NCS optionally includes a barrel forming a slip fit with the cylinder head bore and forming a press fit with the injector tip. The NCS also optionally includes a brim to form a combustion seal with a cylinder head. As the spark plug ignites a fuel charge in the prechamber, heat is absorbed into the injector tip, flows into the NCS barrel, out of the NCS brim, and into the cylinder head for cooling via a cooling jacket.

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 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 hydrogen engine in which hydrogen gas is supplied into a combustion chamber as fuel, comprises: an injector for injecting hydrogen gas; a pressure accumulation chamber communicating with an injection hole of the injector; a communication hole communicating with the pressure accumulation chamber and the combustion chamber; and a pressure accumulation chamber defining portion provided between the injector and the combustion chamber and defining the pressure accumulation chamber and the communication hole. The pressure accumulation chamber defining portion is formed separately from the injector and has a thermal conductivity equal to or higher than a thermal conductivity of a combustion chamber wall defining the combustion chamber.

A hydrogen engine in which hydrogen gas is supplied into a combustion chamber as fuel, comprises: an injector for injecting hydrogen gas; a pressure accumulation chamber communicating with an injection hole of the injector; a communication hole communicating with the pressure accumulation chamber and the combustion chamber; and a pressure accumulation chamber defining portion provided between the injector and the combustion chamber and defining the pressure accumulation chamber and the communication hole. The pressure accumulation chamber defining portion is formed separately from the injector and has a thermal conductivity equal to or higher than a thermal conductivity of a combustion chamber wall defining the combustion chamber.

An igniter assembly comprising an ignition coil assembly connected to a firing end assembly by an extension, with a valve assembly disposed in a pressure chamber of the extension, is provided. The valve assembly includes a valve stem biased toward the ignition coil assembly by a spring to seal the pressure chamber. The valve assembly is used to evacuate contents from the pressure chamber by pressing the valve stem toward the spring and allowing contents of the pressure chamber to travel through and past the valve stem and out of the pressure chamber. The valve assembly is also used to fill the pressure chamber with an insulating medium by pressing the valve stem toward the spring and allowing the insulating medium to travel through and past the valve stem and into the pressure chamber after evacuating the contents out of the pressure chamber.

An auxiliary chamber (51) having a spark plug (54) and an auxiliary fuel injector is formed at the central part of the top surface of the main combustion chamber (2). When making an air-fuel mixture in the auxiliary chamber (51) burn by the spark plug (54), an air-fuel mixture in the main combustion chamber (2) is made to burn by jet flames ejected from the communicating holes (52). The injection ports of the auxiliary fuel injector (53) are oriented toward a tumble flow inflow peripheral region (R) which is located on the peripheral part of the end portion of the auxiliary chamber (51) at a place located on a side where the tumble flow W flows in from the communicating holes (52). When the tumble flow (W) is made to be generated in the main combustion chamber (2) by the tumble flow control valve (48), auxiliary fuel (QF) is injected from the auxiliary fuel injector (53) toward the tumble flow inflow peripheral region (R) of the auxiliary chamber (51).

An example system can include a radio-frequency power source and a resonator. The resonator can be configured to be electromagnetically coupled to the radio-frequency power source and can have a resonant wavelength. The resonator can include: a first conductor, a second conductor, and a dielectric between the first conductor and the second conductor. The resonator can also be configured such that, when the resonator is excited by the radio-frequency power source with a signal having a wavelength proximate to an odd-integer multiple of one-quarter of the resonant wavelength, the resonator provides at least one of a plasma corona or electromagnetic waves. The system can also include a fuel conduit configured to couple to a fuel source and having one or more outlets for expelling fuel, where at least a portion of the fuel conduit is arranged proximate to the dielectric.

A system composed of a water sleeve and a spark plug for an internal combustion engine. The spark plug has a supply passage, a center conductor, an insulator surrounding the center conductor, and a metallic body surrounding the insulator. A center electrode and at least one ground electrode form a spark air gap. In the region of its front end, the spark plug has an external thread for screwing the spark plug into a component of the internal combustion engine and has at least one discharge opening of the supply passage. The spark plug, at its front end, has, attached to the body, a sleeve that contains the external thread; the body has, on its outside, at least one groove that forms a section of the supply passage; and the sleeve has a heat conducting section that contains at least a part of the external thread and that is in contact with the body and covers at least portions of the groove.