Abstract:
A corona ignition system for maintaining a drive frequency approximately equal to the resonant frequency of a corona igniter is provided. The system includes a current sensor, at least two cascaded timers which are electrically independent of a controller, and at least two switches. During operation, the current sensor measures the current at an input of the corona igniter. A conditioned current signal including information related to the zero crossings of the current ultimately activates a pair of the timers which in turn control and drive one of the switches. The conditioned current signal is not processed by the controller before driving the switch.
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:
A corona igniter assembly including an ignition coil assembly, a firing end assembly, and a dielectric compliant member is provided. The dielectric compliant member is compressed between a high voltage insulator of the ignition coil assembly and a ceramic insulator of the firing end assembly. During assembly of the corona igniter assembly, the dielectric compliant member pushes air outwards and forms a hermetic seal between the high voltage insulator and the ceramic insulation. The dielectric compliant member can have a rounded upper surface, which may improve the hermetic seal. Alternatively, or in addition to the rounded surface on the dielectric compliant member, the lower surface of the high voltage insulator can be rounded to push air outwards during assembly and provide a hermetic seal.
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 translation:提供一种用于在导电部件和火花塞的绝缘体之间提供气密接合的导电玻璃密封件。 玻璃密封通过混合玻璃料,粘合剂,膨胀剂和导电金属颗粒而形成。 玻璃料可以包括二氧化硅(SiO 2),氧化硼(B 2 O 3),氧化铝(Al 2 O 3),氧化铋(Bi 2 O 3)和氧化锌(ZnO)。 粘合剂可以包括钠膨润土或硅酸镁铝,聚乙二醇(PEG)和糊精; 膨胀剂可以包括碳酸锂; 并且导电颗粒可以包括铜。 成品玻璃密封件包括总量为50.0至85.0重量(wt。%)的玻璃,并且导电金属颗粒的量为15.0至50.0wt。 %,基于玻璃密封件的总重量。
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:
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:
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:
A corona ignition system for maintaining a drive frequency approximately equal to the resonant frequency of a corona igniter is provided. The system includes a current sensor, at least two cascaded timers which are electrically independent of a controller, and at least two switches. During operation, the current sensor measures the current at an input of the corona igniter. A conditioned current signal including information related to the zero crossings of the current ultimately activates a pair of the timers which in turn control and drive one of the switches. The conditioned current signal is not processed by the controller before driving the switch.
Abstract:
A ceramic insulator for surrounding an electrode of an ignition device, such as a corona igniter or spark plug, is provided. The insulator is formed of a ceramic material including alumina in an amount of 28 to 38 wt. %, silica in an amount of 57 to 67 wt. %, and calcium oxide in an amount of 3 to 7 wt. %, based on the total weight of the ceramic material. The ceramic insulator is typically formed by firing a mixture of Kaolin, calcium carbonate, and silica, wherein the calcium carbonate acts as a flux during firing. The ceramic material has a relative permittivity of about 5.5 to 6.5 and thus improves the electrical efficiency of the ignition device. The ceramic material is also capable of withstanding temperatures of 900 to 1000° C. and has excellent thermal shock resistance, making it suitable for use in internal combustion engines.
Abstract:
A spark plug (20) for igniting a mixture of fuel and air of an internal combustion engine comprises a center electrode (22) and a ground electrode (24). At least one of the electrodes (22, 24) includes a body portion (28, 30) formed of thermally conductive material and a firing tip (32, 34) disposed on the body portion (28, 30). The firing tip (32, 34) includes a ceramic material, providing an exposed firing surface (36, 38). The ceramic material is an electrically conductive, monolithic ceramic material. The ceramic material of the firing tip (32, 34) includes at least one perovskite structure and/or at least one a spinel structure.