A pre-chamber spark plug for a combustion chamber of an internal combustion engine has a pre-chamber which has a plurality of openings and which is fluidically connectable to the combustion chamber via the openings. Two spark gaps are arranged in the pre-chamber via which respective sparks can be formed. The spark gaps are arranged symmetrically distributed in the pre-chamber and a first of the spark gaps is arranged further outwards than the second spark gap along a direction extending perpendicularly to the longitudinal direction of the pre-chamber spark plug.

The present disclosure relates to spark igniter. The igniter includes a terminal end, main body, a firing end, and a fuel connector. The fuel connector allows a supply of fuel to be delivered to the firing end of the igniter. In one embodiment, the firing end includes a central electrode positioned within an insulator and a series of peripherally located electrodes. The insulator preferably includes a polygonal shaped bore for securing the central electrode. Fuel from the fuel connector is delivered to firing end of the igniter and is dispensed from the corners of the polygonal shaped bore. Once dispensed, the fuel combines with air to form a fuel mixture. The fuel mixture is converted into a plasma by applying a high voltage to the electrodes of the firing end. The plasma then combusts the main fuel supply with an associated combustion chamber.

An igniter having at least two electrodes spaced from each other by an insulating member having a substantially continuous surface along a path between the electrodes. The electrodes extend substantially parallel to each other for a distance both above and below said surface. The insulating member has a channel (recess) for receiving at least a portion of a length of at least one of said electrodes below and to said surface of the insulating member. The surface of the insulating member may preferably be augmented with a conductivity enhancing agent. The insulating member and electrodes are configured so that an electric field between the electrodes at said surface does not have abrupt field intensity changes, whereby when a potential is applied to the electrodes sufficient to cause breakdown to occur between the electrodes, discharge occurs at said surface of the insulating member to define a plasma initiation region.

A spark plug includes: a central electrode extending from a front end side to a rear end side along an axis; an insulator including a front end section formed to be a bottomed tube surrounding a tip of the central electrode; a metal shell shaped to be tubular and structured to support the insulator such that the front end section of the insulator projects to the front end side from a front end section of the metal shell; and a plurality of ground electrodes each of which includes a first end forming a discharge gap with the front end section of the insulator and includes a second end connected to the front end section of the metal shell. The plurality of ground electrodes include a pair of ground electrodes different from each other in size of their discharge gaps.

A spark plug combustion ionization sensor for measuring ion current inside the cylinder of an internal combustion engine. The sensor measures ion current which flows when the energy released during combustion ionizes the air inside the cylinder, and thus can detect combustion and emission parameters. The spark plug combustion ionization sensor generally includes an insulated, dedicated sensing electrode, separate from the sparking electrode of a spark plug. The sensing electrode may also be shielded to further reduce interference such as electromagnetic interference (EMI). The use of a dedicated electrode allows for ion current measurement with less electromagnetic noise from the ignition process, and also eliminates the need for circuitry that is typically necessary when the sparking electrode is also used to sense ion current.

A spark plug for an internal combustion engine includes a housing, an insulator, and a center electrode. The center electrode includes an inside electrode portion and an outside electrode portion. The housing includes a ground electrode projecting from a distal end portion of the housing toward the distal end side of the plug at a part in a plug circumferential direction. The outside electrode portion projects along a surface of the insulator tip in a direction away from a boundary with the inside electrode portion and includes a projection, which is capable of causing an electrical discharge between the ground electrode and the outside electrode portion. The projection is formed in a region in the plug circumferential direction. The projection and the ground electrode are located at positions different from each other in the plug circumferential direction.

A spark plug for an internal combustion engine includes a housing, an insulator, a center electrode, a ground electrode, and a plug cover. The housing has a cylindrical shape. The insulator is held on an inner side of the housing. The insulator has a cylindrical shape. The center electrode is held on an inner side of the insulator. The ground electrode forms a discharge gap with the center electrode. The plug cover, together with the housing, configures an auxiliary combustion chamber in which the discharge gap is arranged. The plug cover includes a spray hole that communicates between the inside and outside of the plug cover. The ground electrode is connected to a plurality of locations on an auxiliary-chamber inner wall surface that includes surfaces of the housing and the plug cover that are exposed to the auxiliary combustion chamber.

A spark plug capable of facilitating the growth of a flame kernel. The spark plug including a metal shell; a center electrode retained in the metal shell in an insulated manner; a ground electrode disposed such that a spark gap is formed between the center electrode and an end portion of the ground electrode; and a plug cap that covers the center electrode and the end portion of the ground electrode from the front in a region in front of the metal shell and in which a through hole is formed. An inner surface of the plug cap in a region in front of a back end of the end portion of the ground electrode and an inner surface of the through hole each have an arithmetical mean roughness of less than or equal to 6.3 m.

Disclosed are a flame-ejecting spark plug, and an internal combustion engine and an automobile having same. On the basis of a conventional spark plug, a space near to an electrode is closed to form a cavity (10), an end face is provided with at least one first hole (11), and a side face is provided with at least one second hole (13). A mixture of air and fuel enters the cavity (10) through the first hole (11) and the second hole (13). Electric discharge between the electrodes produces a spark igniting the combustible gas within the cavity (10), and the flame extends in the cavity (10) and the temperature and pressure rise. The flame is ejected from the first hole (11) and the second hole (13) to form a plurality of columnar flames, and the flame penetrates the combustible gas in a combustion chamber and a cylinder to realize stereoscopic ignition, large-area ignition and high-energy ignition of the combustible gas in the combustion chamber.

A spark plug for an internal combustion engine includes a housing, an insulator, and a center electrode. The center electrode includes an inside electrode portion and an outside electrode portion. The housing includes a ground electrode projecting from a distal end portion of the housing toward the distal end side of the plug at a part in a plug circumferential direction. The outside electrode portion projects along a surface of the insulator tip in a direction away from a boundary with the inside electrode portion and includes a projection, which is capable of causing an electrical discharge between the ground electrode and the outside electrode portion. The projection is formed in a region in the plug circumferential direction. The projection and the ground electrode are located at positions different from each other in the plug circumferential direction.