Abstract:
A spark plug, a center electrode therefore and method of construction is provided. The spark plug has a generally annular ceramic insulator extending between a terminal end and a nose end. A conductive shell surrounds at least a portion of the ceramic insulator and a ground electrode having a ground electrode sparking surface is operatively attached to the shell. An elongate center electrode has a body extending between opposite ends, wherein the body is compacted and sintered of a conductive or semi-conductive ceramic material. One of the electrode ends provides a center electrode sparking surface to provide a spark gap between the center electrode sparking surface and the ground electrode sparking surface.
Abstract:
A spark plug electrode material that may be used in spark plugs and other ignition devices including industrial plugs, aviation igniters, glow plugs, or any other device that is used to ignite an air/fuel mixture in an engine. According to an exemplary embodiment, the electrode material includes a refractory metal (for example, tungsten (W), molybdenum (Mo), rhenium (Re), ruthenium (Ru) and/or chromium (Cr)) and a precious metal (for example, rhodium (Rh), platinum (Pt), palladium (Pd) and/or iridium (Ir)), where the refractory metal is present in an amount that is greater than that of the precious metal. This includes, but is certainly not limited to, electrode materials including tungsten-based alloys such as W—Rh and ruthenium-based alloys such as Ru—Rh. Other combinations and embodiments are also possible.
Abstract:
A spark plug having a multilayer firing tip that minimizes the amount of precious metal used and a method of assembling a spark plug with a multilayer firing tip. The firing tip includes a discharge end and a weld end, with the weld end being connected to a center electrode, and more specifically to a base electrode on the center electrode. The weld end has a coefficient of thermal expansion, which is not between the values for the coefficients of thermal expansion for the discharge end and the base electrode. More specifically, the weld end has a coefficient of thermal expansion which is greater than the coefficients of thermal expansion for the discharge end and base electrode. The weld end is formed from Nickel and Chromium with a limited amount of additional elements. The spark plug is assembled by providing a first elongated material formed from the material used for the discharge end and a second elongated material formed from a material used for the weld end. The two materials are then joined to form a single joined material and are severed to create a firing tip. The firing tip is welded to the center electrode of the spark plug and more specifically, the base electrode.
Abstract:
A spark plug (20) includes a center electrode (24) and a ground electrode (22). The electrodes (22, 24) include a core (26) formed of a copper (Cu) alloy and a clad (28) formed of a nickel (Ni) alloy enrobing the core (26). The Cu alloy includes Cu in an amount of at least 98.5 weight percent, and at least one of Zr and Cr in an amount of at least 0.05 weight percent. The Cu alloy includes a matrix of the Cu and precipitates of the Zr and Cu dispersed in the Cu matrix. The Ni alloy of the clad (28) includes Ni in an amount of at least 90.0 weight percent. The Ni alloy also includes at least one of a Group 3 element, a Group 4 element, a Group 13 element, chromium (Cr), silicon (Si), and manganese (Mn) in a total amount sufficient to affect the strength of the Ni alloy.
Abstract:
An electrode for an ignition device formed from a dilute nickel alloy with improved resistance to high temperature oxidation, sulfidation, corrosive wear, deformation and fracture. The electrode includes at least 90% by weight of nickel; zirconium; boron and at least one element from the group consisting of aluminum, magnesium, silicon, chromium, titanium and manganese. The weight ratio of Zr/B may range from about 0.5 to 150, and may include amounts of, by weight of the alloy, 0.05-0.5% zirconium and 0.001-0.01% boron. The oxidation resistance may be improved by the addition of hafnium in an amount that is comparable to the amount of zirconium, which may include an amount of, by weight of the alloy, 0.005-0.2% hafnium. Electrodes of dilute nickel alloys which include aluminum and silicon, as well as those which include chromium, silicon, manganese and titanium, are particularly useful as spark plug electrodes.
Abstract:
A spark plug, center electrode and method of construction is provided. The spark plug has a generally annular ceramic insulator and a conductive shell surrounding at least a portion of the ceramic insulator. A ground electrode is operatively attached to the shell, with the ground electrode having a ground electrode sparking surface. A center electrode has an elongate body with a center electrode sparking surface. The center electrode sparking surface and the ground electrode sparking surface provide a spark gap. The center electrode body is constructed of a composite material including at least one ceramic material.
Abstract:
A spark plug having a multilayer firing tip that minimizes the amount of precious metal used and a method of assembling a spark plug with a multilayer firing tip. The firing tip includes a discharge end and a weld end, with the weld end being connected to a center electrode, and more specifically to a base electrode on the center electrode. The weld end has a coefficient of thermal expansion, which is not between the values for the coefficients of thermal expansion for the discharge end and the base electrode. More specifically, the weld end has a coefficient of thermal expansion which is greater than the coefficients of thermal expansion for the discharge end and base electrode. The weld end is formed from Nickel and Chromium with a limited amount of additional elements. The spark plug is assembled by providing a first elongated material formed from the material used for the discharge end and a second elongated material formed from a material used for the weld end. The two materials are then joined to form a single joined material and are severed to create a firing tip. The firing tip is welded to the center electrode of the spark plug and more specifically, the base electrode.
Abstract:
A spark plug (10) having an elongated ceramic insulator (12) includes numerous design features in various strategic locations. At least the ground electrode (26) is fitted with a rimmed, hemispherical metallic sparking tip (56) which controls rogue electrical arcing (62) and facilitates attachment techniques due to increased surface contact with the ground electrode (26). The various features of the spark plug (10) cooperate with one another so that the physical dimensions of the spark plug (10) can be reduced to meet current demands of newer engines without sacrificing mechanical strength or performance.
Abstract:
A sparkplug having ground and center electrodes that include a firing tip formed from a noble metal or noble metal alloy by reflowing of a noble metal preform. The present invention also includes a method of manufacturing a metal electrode having an ignition tip for an ignition device, including forming a metal electrode having a firing tip portion; applying a noble metal preform to the firing tip portion; and reflowing the noble metal preform to form a noble metal firing tip.
Abstract:
A spark plug (10) for a spark ignited internal combustion engine includes a suppressor seal pack (54) interposed between an upper terminal stud (46) and a lower center electrode (60). The suppressor seal pack (54) includes a top layer of conductive glass (52) surrounding the bottom end (50) of the terminal stud (46) and a lower glass seal layer (58) surrounding a head (62) of the center electrode (60). A resistor layer (56) fills the space between the conductive glass layers (52, 58). The resistor layer (56) has a larger first cross-sectional area (76) at its upper end and a smaller second cross-sectional area (78) at its lower end. A reducing taper (80) establishes a progressive transition between the greater and lesser cross-sectional areas (76, 78). The reducing taper (80) is located in a large shoulder region (LS) which is defined as the longitudinal dimension between the theoretical reference point (70) at the filleted transition (26) and the theoretical reference point (68) at the upper seat (17). The suppressor seal pack (54) is of the fired-in variety in which each layer (54, 56, 58) is separately filled as a granular material, tamped and then cold pressed using the terminal stud (46). The assembly is then heated in a furnace, then removed so that the terminal stud (46) can be used to hot press the suppressor seal pack (54) into a final, operative condition. The suppressor seal pack (54) has a length (SL) which is maximized by use of a positive “A” dimension (+A) defined as the longitudinal distance between the center electrode head (62) seat and the theoretical location (72) of the lower seat (19).