Abstract: A method for making an extruded insulator for a spark plug in a manner that minimizes pores, relics and/or other defects in the insulator microstructure so that the overall dielectric strength or performance of the insulator is improved. The method may be used to manufacture an extruded insulator that avoids many of the drawbacks associated with such defects, but also has a stepped internal bore for receiving a center electrode. In one embodiment, the method uses a multi-phase extrusion process to extrude a ceramic paste around an elongated arbor and form an extruded section, and then removes the arbor from the extruded section to reveal a stepped internal bore.

Abstract: A spark plug has a firing pad attached to a center electrode or to a ground electrode. The firing pad is attached via laser welding and has a sparking surface with an overall fused area and an unfused area. In one or more embodiments, the overall fused area is located in part or more inboard of a peripheral edge of the firing pad.

Abstract: A prechamber spark plug for a gas-powered internal combustion engine having: a metallic body, an insulator, a center conductor connected to a center electrode, a ground electrode, and a cap that is attached to a front end of the body and forms a prechamber. The prechamber can be subdivided into a front part and a back part by an imaginary separating plane that is perpendicular to the center conductor at an end face of the center electrode. The front part of the prechamber is located on the front side of the separating plane, and the back part is located inside the body on the back side of the separating plane so that the volume of the back part is larger than the volume of the front part. Apart from its connection to the front part of the prechamber, the back part is closed in a gas-tight manner.

Abstract: A spark plug for a prechamber internal combustion engine, having: a body with a passage and a front end; a center electrode located in the passage and that projects past the front end; an insulator that surrounds a section of the center electrode and has a tapering front end that together with the passage forms a free annular space within the body; a ground electrode with an annular ignition section that surrounds a section of the center electrode located outside the body, forming a spark gap; the ground electrode has a mounting section connected to the front end of the body, and at least two web sections connecting the ignition section to the mounting section; located between the web sections are scavenging ports through which the annular space is in connection with the environment outside the spark plug.

Abstract: A method for drying a seal material for use in manufacturing an ignition device, e.g., a spark plug. A free-flowing or loose seal material having a moisture content is provided and brought together with a desiccant for a time sufficient to produce a dry seal material by reducing the moisture content of the loose seal material to a desired level. Thereafter, the dry seal material and the desiccant may be separated from one another so that the dry seal material can be used to form a seal within an internal bore of a spark plug.

Abstract: A corona igniter assembly 20 comprises an ignition coil assembly 22, a firing end assembly 24, and a metal tube 26 connecting the ignition coil assembly 22 to the firing end assembly 24. A rubber boot 28 is disposed in the metal tube 26 and compressed symmetrically between a coil output member 30 of the ignition coil assembly 22 and an insulator 42 of the firing end assembly 24. Thus, the rubber boot 28 fills any air gaps and provides a hermetic seal between the ignition coil assembly 22 and the firing end assembly 24 to prevent unwanted corona discharge from forming from those air gaps.

Abstract: An industrial spark plug (20) includes a central electrode (24) with a central base (30) formed of a nickel-based material and a central firing tip (32) formed of an iridium-based material. The central firing tip (32) has a tip thickness (tct) of 0.02 to 0.03 inches, a tip diameter (dct) of 0.1184 to 0.1776 inches, and an aspect ratio of 4.736 to 7.104. The central firing tip (32) is electron beam welded to the central base (30) to provide a robust joint therebetween. The central electron beam weld (36) includes a mixture of re-crystallized iridium-based material and re-crystallized nickel-based material extending continuously along and over the entire welding interface. The spark plug (20) also includes a ground electrode (26) with a ground firing tip (38) electron beam welded to a ground base (42).

Abstract: A welding system for welding small precious metal firing tips to spark plug electrodes, such as ground and/or center electrodes. According to one embodiment, the welding system includes a firing tip storage assembly and a firing tip welding assembly, where the firing tip storage assembly uses pressurized gas introduced at the bottom of a part container to float or lift the firing tips so that the firing tip welding assembly can more easily acquire them with a vacuum-driven nozzle that also doubles as a welding electrode. The firing tip welding assembly is mounted to a robotic apparatus that can index or move the firing tip welding assembly between the firing tip storage assembly, a welding station and/or any other suitable positions.

Abstract: A spark plug for a stationary, gas-powered internal combustion engine, having a metallic body, an insulator mounted in a passage of the body, a center electrode passing through the insulator, a ground electrode mounted on the body that, together with the center electrode, forms a spark air gap, and a cap attached to the body. The cap shields the center and ground electrodes from the combustion chamber after the spark plug is installed in a combustion chamber of the internal combustion engine, and that, together with the body of the spark plug, forms a prechamber in which the center and ground electrodes are located. The cap has at least one opening that permits gas exchange between the prechamber and the space outside of the prechamber.

Abstract: A spark plug for a gas-powered internal combustion engine having: a spark plug body; an insulator; a center electrode; a ground electrode support that is attached to the spark plug body and supports at least one ground electrode that forms a spark gap with the center electrode; a swirl chamber located at the front end of the spark plug whose wall surrounds the center and ground electrodes; the wall of the swirl chamber is formed by a cylindrical sleeve which has an open front face and radial perforations; the ground electrode support includes an annular base part and at least one arm that supports the ground electrode; the arm starts at the base part and extends within the swirl chamber. The arm of the ground electrode support increases in cross-section starting from the ground electrode it supports toward the annular base part of the ground electrode support.

Abstract: A corona discharge ignition system comprising a plurality of corona igniters is provided. The system includes a control and drive electronics unit for directing the energy from a power supply toward the corona igniters; and a single transformer disposed between the control and drive electronics unit and the plurality of corona igniters. A plurality of igniter switching units is connected to the control and drive electronics unit and each igniter switching unit is connected to a separate one of the corona igniters. Each igniter switching unit allows current to travel from the transformer to the one connected corona igniter when activated and prevents current from traveling from the transformer to the one connected corona igniter and from the one connected corona igniter toward the transformer when deactivated. Only one of the igniter switching units is activated at any given time during operation of the system.

Abstract: An igniter (20) includes an outer insulator (24) formed of an outer ceramic material hermetically sealed to a conductive core (26). The conductive core (26) is formed of a core ceramic material and a conductive component, such as an electrically conductive coating applied to the core ceramic material or metal particles or wires embedded in the core ceramic material. The conductive core (26) is typically sintered and disposed in the green outer insulator (24). The components are then sintered together such that the outer insulator (24) shrinks onto the conductive core (26) and the hermetic seal forms therebetween. The conductive core (26) fills the outer insulator (24), so that the conductive core (26) is disposed at an insulator nose end (34) of the outer insulator (24) and the electrical discharge (22) can be emitted from the conductive core (26), eliminating the need for a separate firing tip.

Abstract: The invention provides a system and method for controlling corona discharge and arc formations during a single corona event, i.e. intra-event control. A driver circuit provides energy to the corona igniter and detects any arc formation. In response to each arc formation, the energy provided to the corona igniter is shut off for short time. The driver circuit also obtains information about the arc formations, such as timing of the first arc formation and number of occurrences. A control unit then adjusts the energy provided to the corona igniter after the shut off time and during the same corona event based on the information about the arc formations. For example, the voltage level could be reduced or the shut-off time could be increased to limit arc formations and increase the size of the corona discharge during the same corona event.

Abstract: A spark plug having a front end of a spark plug body that projects over a front end of an insulator, a recess that is arranged at the front end of the insulator from which a center electrode projects and forms an air spark gap with a ground electrode, an annular intermediate space that is formed by the recess between the insulator and the center electrode, and a surface of the recess that runs in an at least partially curved manner between the center electrode and the end of the spark plug body so that the recess forms an insulating section that prevents a sliding spark between the center electrode and the spark plug body.

Abstract: A power amplifier circuit that has an inductor and capacitor connected to one end of the output winding of an RF transformer. The other end of the output winding is connected to a current sensor that in turn is connected to ground. The transformer has two primary windings. Both primary windings have one end connected to a voltage supply. The other end of each primary winding is attached to a switch. All three windings are wound around a core. Current flowing from the DC voltage supply to the switches causes a magnetic flux in the core. A voltage is generated on the secondary winding current sensor by the current that flows through the igniter. This voltage is fed back to the switches, controlling on and off timing. Voltage is provided to the igniter or pulled from the igniter when the current traveling into or from the igniter is at zero.

Abstract: An electrically conductive glass seal for providing a hermetic bond between an electrically conductive component and an insulator of a spark plug is provided. The glass seal is formed by mixing glass frits, binder, expansion agent, and electrically conductive metal particles. The glass frits can include silica (SiO2), boron oxide (B2O3), aluminum oxide (Al2O3), bismuth oxide (Bi2O3), and zinc oxide (ZnO); the binder can include sodium bentonite or magnesium aluminum silicate, polyethylene glycol (PEG), and dextrin; the expansion agent can include lithium carbonate; and the electrically conductive particles can include copper. The finished glass seal includes the glass in a total amount of 50.0 to 85.0 weight (wt. %), and electrically conductive metal particles in an amount of 15.0 to 50.0 wt. %, based on the total weight of the glass seal.

Abstract: A method for producing a spark plug for internal combustion engines, having a metallic shell, a ceramic insulator held in the shell, a center electrode embedded in the insulator, and a ground electrode implemented as a bridge attached to the front end of the shell, wherein an end piece made of a precious metal is attached to the front end of the center electrode and a counterpart is attached to the bridge opposite the end piece, between which is formed a spark gap. A cylindrical body made fully or partially of the precious metal or precious metal alloy intended for the end piece and that is longer than the end piece is welded onto the front end of the center electrode. A bridge is used that has, in the center, a hole, the cross-section of which is matched to the cross-section of the cylindrical body. The bridge is placed on the front end of the shell in such a manner that the forward-facing end of the cylindrical body enters the hole in the bridge.

Abstract: A spark plug having a metal shell, an insulator, a center electrode, a ground electrode, and a multi-layer sparking component. The multi-layer sparking component is attached at a firing end of the ground electrode and includes a thin precious metal layer formed overtop a base metal layer and, according to some embodiments, overhangs the end of the ground electrode. The precious metal and base metal layers may be pre-manufactured together as a bi-metal ribbon, sheet or laminate before the multi-layer sparking component is attached to the ground electrode.

Abstract: An electrode material that may be used in spark plugs and other ignition devices for igniting an air/fuel mixture in an engine. The electrode material has a metal ceramic composite structure and includes a particulate component embedded or dispersed within a matrix component such that the electrode material has a multi-phase microstructure. In an exemplary embodiment, the matrix component includes platinum (Pt) and one or more additive metals like nickel (Ni) or palladium (Pd), and the particulate component includes an electrically conductive ceramic, such as titanium diboride (TiB2). A liquid phase or a solid phase sintering process may be used, depending on the particular constituency of the electrode material.

Abstract: A spark plug has a firing pad attached to a center electrode or a ground electrode by way of a fused portion. In one or more embodiments, the firing pad is composed of a precious metal material. The fused portion can be formed in such a way that a material composition thereof at a sparking surface of the firing pad has a greater percentage of the precious metal material than a material of the underlying electrode to which the firing pad is attached.