Abstract: An improvement in a thermally insulating component for an engine part, made by sintering from ceramic materials, comprises, the thermally insulating component having a composition, consisting of a mixture of zirconium oxide in the range of about 5% to about 25% by volume and mullite in the range of about 75% to about 95% by volume. Further, the mixture of zirconium oxide and mullite is obtained by chemically mixing the zirconium oxide and mullite in their molecular states, rather than mechanically mixing them. Another feature of this invention includes, forming said thermally insulating component by slip casting and pressureless sintering the mixture of zirconium oxide and mullite at a temperature no greater than 1700.degree. C. This improvement in a thermally insulating component for an engine part, made from a mullite-zirconia ceramic composite, embodying the present invention, is particularly useful in making flame decks for cylinder heads, and insulating coverings for pistons and exhaust ports.

Abstract: A spark plug for forming a spark that jumps between two electrodes has an insulating body surrounded by a housing with a ground electrode. The insulating body has a center electrode therein, which projects beyond the ground electrode in the axial direction.

Abstract: A spark plug (80) having a center electrode (82) with a cylindrical body and having a tip (84) at one end and a terminal (123) near the other end with an insulator (86) extending around the center electrode (82). A ground shield and retainer unit extends around the insulator (86) and includes a threaded portion (88) near one end and a ground electrode (85) near the other end, having a portion thereof aligned with the center electrode tip (84) to form a spark gap, with a sealing portion (92) disposed therebetween for sealing the engine combustion chamber from the outside environment when the spark plug (80) is installed. The ground shield and retainer unit can be formed from two parts (88,90) which are deformed during manufacturing to be in mechanical engagement and securely holding the insulator (86) in place. The spark plug (80) can also have two or more center electrodes (82,84) with two or more corresponding ground electrodes (83,85) projecting from the ground shield (90).

Abstract: A cylinder head and spark plug assembly for mounting on an engine block to create a combustion chamber for burning fuel and method for assembling the same are disclosed. A cylinder head has an end wall with an exterior surface and an interior surface and a spark plug bore extending downstream from the exterior surface to the interior surface. The spark plug bore has a seal surface adjacent the interior surface and external threads disposed upstream from the seal surface. A spark plug includes a body terminating in an end portion having a seal surface thereon, a nut and external threads disposed between the nut and the seal surface. The external threads of the spark plug are threadedly retained within the internal threads of the spark plug bore with the spark plug seal surface cooperating with the cylinder head seal surface in an interference fit eliminating any crevice between the end portion of the body and the spark plug bore downstream of the interference fit.

Abstract: An ignition plug of this invention is characterized in that a ground electrode thereof has a recess that faces the side surface of a single center electrode; more particularly, in the case of an L-shaped ground electrode whose free end is opposed to the center electrode with a spark gas in between, the recess is provided to on the free end of the ground electrode so that it can hold plentiful gas mixture to ignite near the spark gap by increasing its capacity with the increase of distance from the side surface of the center electrode; thus, the farther the igntion proceeds into the recess, the more intensively gas mixture is ignited, whereby instantaneous combustion can be caused in the entire space of a combustion chamber.

Abstract: Automotive spark plug having an injection molded body which includes the central electrode and connnecting cap and the grounded electrode. In one embodiment, the grounded electrode is secured to a threaded metal cap which is mounted on a band integral with the molded body, and which has support legs extending into the molded body. In a second embodiment, the molded body is appropriately threaded and the grounded electrode extends into the interior radius of the threads so as to provide a proper ground.

Abstract: An ignition system providing both spark ignition and a hot surface for surface ignition of a stratified fuel charge. The ignition system includes a novel hot surface spark plug designed to maximize heat retention in the center electrode and surrounding insulator for enabling surface ignition over a portion of the operating cycle of the engine. Ignition power is applied only when the center electrode temperature is below a threshold temperature. When the center electrode temperature is above a threshold temperature, ignition power is applied in inverse relation to the center electrode temperature.

Abstract: The invention teaches an ignition device for internal combustion engines, comprising at least one spark gap with two ignition electrodes for generating ignition sparks between them, whereby neither of the two ignition electrodes is connected to the ground potential of the internal combustion engines; an ignition current source which is coupled to the ignition electrodes, insulated from ground, to generate the sparks, and forming an ignition circuit therewith; a voltage source, which has one pole at ground, while its other pole is connected to the ignition circuit, so that the ignition circuit is at the same potential as the voltage source and a separate plasma circuit is formed which comprises the voltage source, at least one of the two electrodes, a plasma composed of hot combustion gases between the ignition electrodes and ground, in a series circuit; and means in the plasma circuit which deliver an output pulse corresponding to the strength and time pattern of the current in the plasma circuit.

Abstract: An improved ignition apparatus for an internal combustion engine includes at least an ignition coil and a first electrode assembly and a second electrode assembly, each thereof including an electrode, and each of the electrodes of the first and second electrode assemblies is electrically connected to one end of a secondary winding of an ignition coil. The electrodes are supported on a cylinder head of the engine being electrically insulated therefrom and they form a spark gap for producing spark discharge therebetween, and a high tension circuit connecting the electrodes to the secondary winding of the ignition coil is electrically insulated from the body of the engine. The ignition apparatus having the above-described construction has the functional effects of improving the ignition performance, simplifying the withstant voltage design of constituent components, improving the antifouling performance at a spark gap portion and increasing the radio frequency interference suppression performance.

Abstract: An improved ignition apparatus for an internal combustion engine includes at least an ignition coil and a first electrode assembly and a second electrode assembly, each thereof including an electrode, and each of the electrodes of the first and second electrode assemblies is electrically connected to one end of a secondary winding of an ignition coil. The electrodes are supported on a cylinder head of the engine being electrically insulated therefrom and they form a spark gap for producing spark discharge therebetween, and a high tension circuit connecting the electrodes to the secondary winding of the ignition coil is electrically insulated from the body of the engine. The ignition apparatus having the above-described construction has the functional effects of improving the ignition performance, simplifying the withstant voltage design of constituent components, improving the antifouling performance at a spark gap portion and increasing the radio frequency interference suppression performance.

Abstract: The present invention provides a hot spark that is more-or-less uniform over the combustion chamber volume in a liquid oxidant/liquid fuel combustion engine. In addition, heat losses are reduced and low wear/low friction surfaces are provided. Flame sprayed ceramic coatings are utilized to provide all embodiments of the present invention.

Abstract: An improved method and apparatus for effecting the ignition of a relatively lean air-fuel mixture includes a pair of electrode gaps at which strong electrostatic fields of relatively long duration are established to accumulate fuel particles in a portion of a combustion chamber adjacent to a spark gap. In one embodiment of the invention, one of the electrode gaps is enclosed so that the atmosphere in this gap is not affected by changes in the pressure and composition of the atmosphere in the combustion chamber. By maintaining the atmosphere in the electrode gap separate from the atmosphere in the combustion chamber, an electrostatic field of substantially constant strength can be maintained at the enclosed electrode gap after the establishment of a corona discharge at an electrode gap exposed to the atmosphere in the combustion chamber. In another embodiment of the invention, both of the electrode gaps are exposed to the atmosphere in the combustion chamber.