A firing tip for a corona igniter is provided. The firing tip includes a base formed of metal, such as nickel, and rivets formed of precious metal, such as iridium. The base includes indentations, and the rivets are disposed in the indentations of the base. The rivet has a melting point and/or wear resistance greater than the base. Typically, the indentations of the base include a concave surface and the rivets have a cylindrical shape matching the shape of the indentations. The rivets can be sharpened to a point. The rivets can include a first piece formed of precious metal and a second piece formed of nickel or nickel alloy, wherein an end of the first piece is welded to an end of the second piece, and the second piece is welded to the base. Alternatively, the rivets can be formed entirely of the precious metal.

An insulator for a corona igniter, referred to as a barrier discharge ignition (BDI) device, for use in an internal combustion engine, is provided. A central electrode is disposed in a slot of the insulator and an electrode tip is spaced from a round insulator tip by insulating material. A shell formed of metal surrounds a portion of the insulator. The insulator has a thickness tapering between a shell firing surface and the insulator tip. The tapering insulator thickness is unidirectional and thus does not increase between a start of the taper and the insulator tip. A method of manufacturing an insulator for a corona igniter is also provided. Equations can be used to determine if a taper in the insulator thickness is needed to encourage corona propagation along a core nose projection of the insulator, and if so, the location and size of the taper.

An ignition system and a method for a spark-ignition combustion engine having a high-frequency plasma-augmented ignition spark, the spark ignition of the fuel being realized by at least one spark plug associated with a combustion chamber of the combustion engine. The spark plug has a prechamber having at least one opening via which the prechamber communicates with the combustion chamber on the fuel side, so that the ignition spark in the prechamber, into which the high-frequency plasma can be injected, induces the plasma-augmented spark ignition of the fuel in the prechamber.

An ignition system and a method for a spark-ignition combustion engine having a high-frequency plasma-augmented ignition spark, the spark ignition of the fuel being realized by at least one spark plug associated with a combustion chamber of the combustion engine. The spark plug has a prechamber having at least one opening via which the prechamber communicates with the combustion chamber on the fuel side, so that the ignition spark in the prechamber, into which the high-frequency plasma can be injected, induces the plasma-augmented spark ignition of the fuel in the prechamber.

An internal combustion engine includes a fuel nozzle for injecting a fuel into a combustion chamber, and a plasma igniter for generating one or more pluralities of free radicals within the chamber, and initiating a flame to ignite the fuel. The igniter protrudes into the chamber. A method of igniting a fuel within a combustion chamber and controlling combustion phasing includes injecting a first portion of the fuel into the combustion chamber, energizing the plasma igniter to generate one or more pluralities of free radicals, each plurality having a known voltage, subsequently injecting a second portion of the fuel into the combustion chamber, and closely coupling activation of the plasma igniter with the second injection to ignite the fuel. Combustion phasing of the ignition event is controlled by controlling the number and voltage of the pluralities of free radicals generated by the plasma igniter.

An internal combustion engine includes a fuel nozzle for injecting a fuel into a combustion chamber, and a plasma igniter for generating one or more pluralities of free radicals within the chamber, and initiating a flame to ignite the fuel. The igniter protrudes into the chamber. A method of igniting a fuel within a combustion chamber and controlling combustion phasing includes injecting a first portion of the fuel into the combustion chamber, energizing the plasma igniter to generate one or more pluralities of free radicals, each plurality having a known voltage, subsequently injecting a second portion of the fuel into the combustion chamber, and closely coupling activation of the plasma igniter with the second injection to ignite the fuel. Combustion phasing of the ignition event is controlled by controlling the number and voltage of the pluralities of free radicals generated by the plasma igniter.

A combustion test system includes a power source and a corona generator coupled to the power source. The combustion test system also includes a charge storage device. The charge storage device includes a charging surface spaced apart from the corona generator such that charge carriers, motivated by an electric field of the corona generator, intersect the charging surface to charge the charge storage device. The combustion test system also includes a first electrode coupled to the charge storage device and a second electrode coupled to a reference ground. The second electrode is spaced apart from the first electrode to produce an electrical arc between the first electrode and the second electrode based on a voltage difference between the first electrode and the second electrode.

A combustion test system includes a power source and a corona generator coupled to the power source. The combustion test system also includes a charge storage device. The charge storage device includes a charging surface spaced apart from the corona generator such that charge carriers, motivated by an electric field of the corona generator, intersect the charging surface to charge the charge storage device. The combustion test system also includes a first electrode coupled to the charge storage device and a second electrode coupled to a reference ground. The second electrode is spaced apart from the first electrode to produce an electrical arc between the first electrode and the second electrode based on a voltage difference between the first electrode and the second electrode.

An ignition device ignites a mixture of air and fuel gas by plasma to generate an initial flame. The ignition device includes a spark plug having an inner conductor, a cylindrical outer conductor that holds the inner conductor inside, and a dielectric provided between the inner conductor and the outer conductor, and the spark plug configured to emit an electromagnetic wave to a plasma formation space between the inner conductor and the outer conductor to generate a plasma. The ignition device includes an electromagnetic wave power supply that generates the electromagnetic wave by inputting the electromagnetic wave power Ps to the spark plug and a power supply control unit that controls the electromagnetic wave power supply. The electromagnetic wave power supply is configured to generate high frequency power at a number of different frequencies. The power supply control unit outputs at least one of the plurality of high frequency powers generated by the electromagnetic wave power supply as the electromagnetic wave power.

A spark plug includes: a center electrode; an insulator having a through hole around a part of the center electrode; and a metal shell holding the insulator from an outer peripheral side thereof. The metal shell includes a shelf portion that projects radially inward. The insulator includes an engagement portion engaged with the shelf portion from the front side, and a front end portion at the front side with respect to a front end of the metal shell. The front end portion has an outer diameter larger than an inner diameter of the metal shell at the front side with respect to the shelf portion. The front end portion of the insulator has a diameter-enlarged portion at which a diameter of the through hole increases and which is spaced apart from an outer peripheral surface of the center electrode.