Abstract: A spark plug includes a ceramic component, whose surface is at least in part coated with a glaze, with the glaze containing 0.6% to 4% by weight of fluoride and 6% to 11.2% by weight of zinc oxide.

Abstract: A spark plug includes a ceramic component, whose surface is at least in part coated with a glaze, with the glaze containing 0.6% to 4% by weight of fluoride and 6% to 11.2% by weight of zinc oxide.

Abstract: A spark plug includes a ceramic component, whose surface is at least in part coated with a glaze, with the glaze containing 0.6% to 4% by weight of fluoride and 6% to 11.2% by weight of zinc oxide.

Abstract: The seal between the insulator and the center electrode is to be improved in a spark plug for an internal combustion engine comprising a shell (12), an insulator (16) located in the shell and composed of a sintered ceramic material, as well as a center electrode (18) and a terminal stud (22) that have an electrically conductive connection with each other and are located in the insulator. For this purpose, it is provided that a cermet (28) abuts the center electrode, the ceramic phase of which is composed of the same or a similar material as the insulator, and the metallic phase of which is composed of a material having good electrical conductivity. Since the material properties of the cermet are similar to those of the insulator—the thermal expansion, in particular, is same—a particularly good seal is created between the cermet and insulating body.

Abstract: A spark plug includes a ceramic component, whose surface is at least in part coated with a glaze, with the glaze containing 0.6% to 4% by weight of fluoride and 6% to 11.2% by weight of zinc oxide.

Abstract: A glass ceramic, for use as a resistor or a gas-tight glass ceramic solder for use in a spark plug, includes a fused seal of a starting glass fused from a starting mixture containing SiO2, Al2O3, TiO2 and CaO, the fused seal including crystalline phases in at least some areas. A method for producing such a glass ceramic provides for the starting glass to be processed in a first method step to form a starting material, which is heated for a first period of time in a second method step from a starting temperature, which is below the softening temperature of the starting glass, to a fusion temperature, which is above the softening temperature of the starting glass, and is kept at that temperature for a second period of time and finally is cooled again. A spark plug may include a terminal stud and a center electrode, which are electrically connected across a resistor that is formed in at least some areas by the glass ceramic.

Abstract: A glass or glass powder is fused from a starting mixture containing approximately 38 wt % to 48 wt % SO2, 15 wt % to 19 wt % Al2O3, 4.5 wt % to 11 wt % TiO2, 0 wt % to 1.5 wt % Na2O, 0 wt % to 1.5 wt % K2O and 23 wt % to 30 wt % CaO. In addition, a glass powder mixture includes two glass powders, a carbon black powder and an organic binder, the first glass powder having a mean particle size of approximately 150 &mgr;m to 250 &mgr;m, the second glass powder having a mean particle size of less than approximately 100 &mgr;m, which may be 10 &mgr;m to 70 &mgr;m. The glass or glass powder mixture is suitable for producing a glass ceramic, such as that used as a resistor seal and/or a gas-tight glass ceramic solder in a spark plug.

Abstract: A spark plug with a metallic housing (10) is proposed, which has an insulator (11) embedded in the housing (10), in which a rod-shaped internal conductor device is disposed. The internal conductor device has a contact pin (13), a current-limiting erosion resistor (17), and a central electrode (14). A sealing material (16) secures the central electrode (14) in a sealed fashion in the insulator (11). The temperature resistant sealing material (16) essentially contains at least one metallic component and at least one ceramic component with a low thermal expansion, wherein the metallic component has a melting temperature that is higher than the operating temperature.

Abstract: A spark plug having a tubular metallic housing has an internal conductor arrangement including a refractory erosion. The refractory erosion resistor is designed either as a wound wire resistor or a filament-like thin-layer resistor.

Abstract: The seal between the insulator and the center electrode is to be improved in a spark plug for an internal combustion engine comprising a shell (12), an insulator (16) located in the shell and composed of a sintered ceramic material, as well as a center electrode (18) and a terminal stud (22) that have an electrically conductive connection with each other and are located in the insulator. For this purpose, it is provided that a cermet (28) abuts the center electrode, the ceramic phase of which is composed of the same or a similar material as the insulator, and the metallic phase of which is composed of a material having good electrical conductivity. Since the material properties of the cermet are similar to those of the insulator—the thermal expansion, in particular, is same—a particularly good seal is created between the cermet and insulating body.

Abstract: A spark plug having an electrode connected via a terminal stud to an ignition lead and having a resistor arranged between the electrode and the ignition lead, the resistor having increased temperature resistance.

Abstract: A glass ceramic which is especially suitable as a resistor (5) or a gas-tight glass ceramic solder (9) in a spark plug (1) is described. The glass ceramic here is a fused seal of a starting glass which is fused from a starting mixture containing SiO2, Al2O3, TiO2 and CaO. The fused seal also has crystalline phases in at least some areas. In addition, a method is described for producing such a glass ceramic, the starting glass being processed in a first method step to form a starting material. This starting material is then heated for a first period of time in a second method step from a starting temperature, which is below the softening temperature (Tg) of the starting glass, to a fusion temperature, which is above the softening temperature (Tg) of the starting glass, and is kept at that temperature for a second period of time and finally is cooled again.

Abstract: A spark plug having a tubular metallic housing in which an insulator is embedded, a rod-shaped internal conductor configuration being arranged in the insulator. The internal conductor configuration includes a terminal stud, a current-limiting resistor embedded in a conductive contact compound, a contact pin and a center electrode. The current-limiting resistor has two regions of unequal diameter. The diameter is smaller in the region nearer the combustion chamber than in the region farther from the combustion chamber.

Abstract: A spark plug having a tube-shaped, metal housing, an insulator which is retained by the housing, and an inner conductor arrangement embedded in the insulator, the inner conductor arrangement comprising one connection bolt, one burn-off resistor, one contact pin, and one platinum central electrode, and four ground electrodes, which are bent towards the central electrode and protrude beyond the insulator by the width of their thickness, being secured to the housing, the contact pin being coated and being shortened in its length such that the burn-off resistor is forward-positioned as far as possible towards the spark gap, and the platinum central electrode having a nail shape, whose rear part has a smaller diameter than its front part, which extends out of the insulator.

Abstract: An electrically conducting sealing compound for a sparkplug contact core with the sealing compound being disposed between a terminal-side section and a spark-side section of a center electrode, while the sealing compound essentially contains a fusible glass component and a powdered, electrically conducting component. The electrically conducting component of the sealing compound is exclusively composed of graphite in an amount of 10 to 30% by volume, based on the powder components of the sealing compound.

Abstract: To securely seat a ceramic electrode (23, 28) in an insulator (15) of a spark plug, so that it can be sintered together with the insulator, a ceramic plug element (28) has added thereto an additive which renders the ceramic plastically deformable upon application of external energy; the additive may, for example, be a thermoplastic, which permits plastic deformation upon application of heat; or a thixotropic agent, such as glycerin, rendering the material plastically deformable when vibrated. A pellet or plug (28) is introduced into the end portion (32) of the central opening (21) of the insulator, preshaped to be slightly smaller by, for example, 0.2 mm, than the clearance opening in the insulator. The plug is then rendered plastically deformable, compressed by a plunger (34/1) acting against a counter plate (33).

Abstract: A sparkplug for internal combustion engines which has a central electrode extending to the ignition end. The central electrode has an electrically non-conductive core pin with an electrically conductive outer layer on the cylindrical surface of the core pin. The central electrode is positioned in the lengthwise bore of the sparkplug insulator portion, preferably without any clearance between the insulator and the ignition end portion of the central electrode. The core pin is preferably made of a material which has shrinkage characteristics and a thermal coefficient of expansion substantially the same as those of the insulator. Most preferably the same material is used for both components. The electrically conductive coating layer of the central electrode is preferably a conductive metal-ceramic mixture. The coating layer may be in the form of a resistance element and/or contain a pre-ignition discharge gap.

Abstract: A solid closed ended tubular oxygen sensor element, particularly useful for sensing the oxygen content of exhaust gases from internal combustion engines. The closed end of the tubular element which is adapted to be exposed to the hot exhaust gases is made of zirconium oxide stabilized with yttrium oxide and/or ytterbium dioxide. The remaining main portion of the tubular element is made of zirconium dioxide stabilized with calcium oxide. The invention also provides methods of manufacturing these tubular elements.

Abstract: To permit simple manufacture and reliable attachment of the center electrode into a ceramic body, an elastic tubular press mold is located in a press body, the press mold being closed off by a movable plug having a needle-like extension with a gripping end formed thereon to receive the center electrode before the plug is inserted into the tubular mold. Ceramic material is then filled into the mold, the plug closing off one end thereof, the mold is closed with a second plug, and pressure in the order of from 250 to 400 bar applied to the outside of the elastic mold to compress the ceramic material and embed the center electrode tip therein. Upon release of pressure, the compressed ceramic, with the center electrode therein can be removed from the holding tip of the needle-like extension of the plug, for subsequent grinding to size, sintering, firing, and glazing, if desired.

Abstract: Electro-chemical sensor to determine oxygen concentration in hot internal combustion exhaust gases in the form of a closed, tubular element having a solid ion conductive electrolyte; an electron-conductive coating on the inner surface thereof; a porous or fissured electron conductive layer on the outer surface of said solid electrolyte or on a part of said surface, part of the pores or fissures being macroporous, said layer being of a material which catalyzes the formation from said hot exhaust gases of those compounds that are thermodynamically stable at the exhaust temperature; and a porous protective electrically insulating coating on said porous electron-conductive layer. Preferably, a top coating of a heat-resistant metal is applied, which top coating has additionally properties to act as a getter with respect to poisons affecting the catalyzing material.