Abstract: To alleviate or eliminate a problem of unburned fuel discharged to the outside of a cylinder in a case in which an air fuel mixture is insufficiently combusted in a combustion chamber. During the expansion stroke in which a high voltage is applied to an ignition plug via an ignition coil, and a spark discharge is caused to occur at the ignition plug, thereby the air fuel mixture in the combustion chamber is ignited and combusted, in a case in which deterioration of combustion state is detected, a microwave electric field is created in the combustion chamber prior to an opening timing of an exhaust valve at an end stage of the expansion stroke, thereby plasma is generated and enlarged in the combustion chamber.

Abstract: A spark plug is provided, which includes a housing, an insulation porcelain, a center electrode, a main ground electrode, a first sub ground electrode and a second sub ground electrode. The first and second sub ground electrode are arranged being opposed to each other. Requirements of Hs1<Hc+Gm, Gm<Gs1+Gg, Gm<Gs2+Gg, Hs2?Hs1 and Hc<Hs2 are satisfied, where Hc is the length of projection of the center electrode, Gm is the size of the main gap, Hs1 is the length of projection of the first sub ground electrode, Hs2 is the length of projection of the second sub ground electrode, Gs1 is the length of the first sub gap in the radial direction of the plug, Gs2 is the length of the second sub gap in the radial direction of the plug, and Gg is the distance between an outer peripheral edge portion and an inner peripheral edge portion of a porcelain tip portion in the radial direction of the plug.

Abstract: The size of the plasma produced by a plasma-generating device that generates plasma using electromagnetic (EM) radiation is enlarged. The plasma-generating device has an EM-wave-generating device that generates EM radiation, a radiation antenna that emits the EM radiation supplied from the EM-wave-generating device to a target space, and a receiving antenna located near the radiation antenna. The receiving antenna is grounded such that an adjacent portion that is close to the radiation antenna has a higher voltage while the EM radiation is emitted from the radiation antenna. The plasma-generating device generates plasma in the target space near the radiation antenna and the adjacent portion by emitting EM radiation from the radiation antenna.

Abstract: A corona igniter (20) comprises a central electrode (22) surrounded by an insulator (26), which is surrounded by a conductive component. The conductive component includes a shell (34) and an intermediate part (36) both formed of an electrically conductive material. The intermediate part (36) is typically attached to a lower ledge (52) of the insulator outer surface (50) prior to inserting the insulator (26) into the shell (34). The shell firing end (56) is typically aligned with the lower edge and the intermediate firing end. The conductive inner diameter (Dg) is less than an insulator outer diameter (Dio) directly below the lower ledge (52) such the insulator thickness (ti) increases toward the electrode firing end (40).

Abstract: Spark plug for an internal combustion engine, having a center electrode and a ground electrode arranged in radial direction around the center electrode, wherein an annular spark gap is formed between the center electrode and the ground electrode for igniting a fuel mixture by means of an electric ignition spark developing between the center electrode and the ground electrode, and wherein the ground electrode is contoured in such a way that particles reaching the region of the ground electrode can be removed from the spark gap under the influence of gravitational force.

Abstract: A control apparatus for an ignition system of an internal combustion engine which can appropriately judge deterioration of a spark plug is disclosed. The ignition system includes a spark plug and a Zener diode. These are connected in parallel. In the ignition system, a constant-voltage path whose one of two ends is grounded is connected to the connecting path which connects the center electrode of the spark plug to a secondary coil. The constant-voltage path includes a Zener diode and a resistor. In a case where electric current is detected at the resister in a term from the start of current supply to a primary coil to the end, the control apparatus judges the spark plug being deteriorated.

Abstract: An engine for combusting fuel that has a head mounted to an engine block with a gasket disposed therebetween. A chamber is formed within the engine block and head that is frustroconical in shape to direct the energy wave created by the fuel to a reciprocating piston that is disposed within the chamber in the engine block. The gasket has electrical components therein including at least one electrode that extends into the chamber such that when activated the electrode provides a spark in the chamber.

Abstract: An ignition device having an electrode structure including an anode, a cathode, an auxiliary electrode, an anode coating, an auxiliary electrode coating, and an anode supporting body. A coated surface of the anode is opposed to a coated surface of the auxiliary electrode with the anode coating, a combustion space, and the auxiliary electrode coating therebetween. An exposed surface of the anode is opposed to an exposed surface of the cathode with the combustion space therebetween. A distance D1 from the coated surface of the anode to the coated surface of the auxiliary electrode via the anode coating, the combustion space, and the auxiliary electrode coating is shorter than a distance D2 from the exposed surface of the anode to the exposed surface of the cathode via the combustion space (D1<D2). A combustion bomb may be used as the cathode.

Abstract: An ignition source for initiating combustion is provided. The ignition source includes an electrical delivery conductor mounted in a delivery conductor mounting structure. An electrical ground conductor is mounted in a ground conductor mounting structure and extends from the ground conductor mounting structure to a point proximate the delivery conductor to define an ignition spark gap between the delivery conductor and the ground conductor. At least one of the delivery conductor and the ground conductor are mounted in a respective one of the delivery conductor mounting structure and the ground conductor mounting structure so as to be selectively positionable with respect to the other one of the delivery conductor and the ground conductor to selectively adjust a width of the ignition spark gap.

Abstract: An igniter (20) emitting an electrical field including a plurality of streamers forming a corona includes a corona enhancing tip (52) at an electrode firing end (28). The corona enhancing tip (52) includes an emitting member (58) such as a wire, layer, or sintered mass, formed of a precious metal and disposed on a base member (54). The base member (54) is formed of a nickel alloy. The emitting member (58) has a lower electrical erosion rate and chemical corrosion rate than the base member (54). The emitting member (58) presents the smallest spherical radius of the corona enhancing tip (52) at the outermost radial point (56) to concentrate the electrical field emissions and provide a consistently strong electrical field strength over time.

Abstract: A high-voltage generator device, including an inductive-capacitive resonator capable of producing a high voltage, a mechanism generating a high-frequency control pulse train, a voltage source, a capacitor, and a voltage generator including a switching transistor, the control electrode of which is connected to the output of the mechanism generating the high-frequency control pulse train, the source of the switching transistor being connect to ground, and the drain of the switching transistor being capable of delivering a voltage pulse train to the inductive-capacitive resonator in response to the control pulse train received on the control electrode of the switching transistor. The drain of the switching transistor is connected to the inductive-capacitive resonator via an isolating transformer, the isolating transformer being connected in parallel with a capacitor, the isolating transformer also being connected to the voltage source.

Abstract: An alumina sintered body comprises alumina crystals as a main phase and a grain boundary phase made up of crystalline Y2Si2O7 and amorphous SiO2 at grain boundaries of the alumina crystals wherein when the alumina sintered body is taken as 100 wt %, the high melting phase is present in the range of from 0.1 wt % to 15 wt %. There is also provided a method for preparing the alumina sintered body, which method comprising a first mixing step P1 of mixing, at least, a yttria powder having an average particle size of 60 to 100 nm and a silica powder having a given average particle size to provide a mixed slurry and a second mixing step of further mixing an alumina powder having an average particle size of 0.5 to 1.0 ?m in the mixed slurry.

Abstract: An ignition source for initiating combustion is provided. The ignition source includes an electrical delivery conductor mounted in a delivery conductor mounting structure. An electrical ground conductor is mounted in a ground conductor mounting structure and extends from the ground conductor mounting structure to a point proximate the delivery conductor to define an ignition spark gap between the delivery conductor and the ground conductor. At least one of the delivery conductor and the ground conductor are mounted in a respective one of the delivery conductor mounting structure and the ground conductor mounting structure so as to be selectively positionable with respect to the other one of the delivery conductor and the ground conductor to selectively adjust a width of the ignition spark gap.

Abstract: An ignition source for initiating combustion is provided. The ignition source includes an electrical delivery conductor mounted in a delivery conductor mounting structure. An electrical ground conductor is mounted in a ground conductor mounting structure and extends from the ground conductor mounting structure to a point proximate the delivery conductor to define an ignition spark gap between the delivery conductor and the ground conductor. At least one of the delivery conductor and the ground conductor is mounted so as to be positionable with respect to the other one of the delivery conductor and the ground conductor to selectively adjust a width of the ignition spark gap.

Abstract: An igniter for an internal combustion engine is disclosed. The igniter may have a body, and a pre-combustion chamber integral with the body and having at least one orifice. The igniter may also have at least one electrode associated with the pre-combustion chamber. The at least one electrode may be configured to direct RF energy to lower an ignition breakdown voltage requirement of an air and fuel mixture in the pre-combustion chamber. The RF energy alone may be insufficient to ignite and sustain combustion of the air and fuel mixture. The at least one electrode may also be configured to generate an arc that extends to an internal wall of the pre-combustion chamber and ignites the air and fuel mixture.

Abstract: An igniter for an internal combustion engine is disclosed. The igniter may have a body, and a pre-combustion chamber integral with the body and having at least one orifice. The igniter may also have at least one electrode extending into the pre-combustion chamber. The at least one electrode may be configured to direct an arc to an annular side wall of the pre-combustion chamber, and may be movable to adjust an arc termination location on the annular side wall of the pre-combustion chamber.