摘要:
A spark plug having ground and center electrodes that include a firing tip formed from an alloy containing platinum, tungsten, and yttrium oxide. The firing tip can take the form of a pad, rivet, ball, wire, or other shape and can be welded in place on the electrode. The firing tip provides good erosion resistance, a reduced sparking voltage, good welding and forming characteristics, as well as a minimal occurrence of oxidation of the alloy at the weld area. Desirable ranges of the relative amounts of platinum, tungsten, and yttrium are also disclosed.
摘要:
A spark plug (24) of an internal combustion engine is provided with an integrated capacitor feature to increase the intensity of its spark. The capacitor feature is formed by applying metallic film (62, 64) to the inner (30) and outer surfaces of a tubular insulator (26). The insulator (26) forms a dielectric and sustains an electrical charge when an electrical differential is established between the inner (64) and outer (62) metallic films. The stored electrical charge is discharged with the firing of a spark. The metallic films can be applied as a paint or ink directly to the surfaces of the insulator (26), or can be mixed with a glazing compound to form conductive coatings simultaneous with the glazing operation. Ganged (62′) or serpentine (62″) micro-plates can be formed within either or both of the inner and outer metallic films to increase the charge-carrying surface area.
摘要:
An igniter (20) emitting an electrical field including a plurality of streamers forming a corona includes a corona enhancing tip (52) at an electrode firing end (28). The corona enhancing tip (52) includes an emitting member (58) such as a wire, layer, or sintered mass, formed of a precious metal and disposed on a base member (54). The base member (54) is formed of a nickel alloy. The emitting member (58) has a lower electrical erosion rate and chemical corrosion rate than the base member (54). The emitting member (58) presents the smallest spherical radius of the corona enhancing tip (52) at the outermost radial point (56) to concentrate the electrical field emissions and provide a consistently strong electrical field strength over time.
摘要:
A corona igniter 20 with improved temperature control at the firing end is provided. The corona igniter 20 comprises a central electrode 24 include a core material 30, such as copper, surrounded by a clad material 32, such as nickel. The core material 30 extends longitudinally between an electrode terminal end 34 and an electrode firing end 36. The core material 30 is disposed at the electrode terminal end 34 and has a core length Ic equal to at least 90% of an electrode length Ie of the central electrode 24. At least 97% of the core length Ic is surrounded by an insulator 26. The electrode diameter is increased, such that a clad thickness tcl of the central electrode 24 is equal to at least 5% of an insulator thickness ti, and a core diameter Dc is equal to at least 30% of the insulator thickness ti.
摘要:
A corona igniter 20 includes an electrode gap 28 between the central electrode 22 and the insulator 32 and a shell gap 30 between the insulator 32 and the shell 36. An electrically conductive coating 40 is disposed on the insulator 32 along the gaps 28, 30 to prevent corona discharge 24 in the gaps 28, 30 and to concentrate the energy at a firing tip 58 of the central electrode 22. The electrically conductive coating 40 is disposed on an insulator inner surface 64 and is spaced radially from the electrode 22. The electrically conductive coating 40 is also disposed on the insulator outer surface 72 and is spaced radially from the shell 36. During operation of the igniter 20, the electrically conductive coating 40 provides a reduced voltage drop across the gaps 28, 30 and a reduced electric field spike at the gaps 28, 30.
摘要:
A corona ignition system 20 includes a corona drive circuit 26 and an auxiliary energy circuit 28. The energy circuit 28 stores energy during a standard corona ignition cycle. When arc discharge occurs or corona discharge switches to an arc discharge, the energy circuit 28 discharges the stored energy to the electrode 30 to intentionally maintain a robust arc discharge 29 and thus provide reliable ignition. The stored energy is transmitted to the electrode 30 over a predetermined period of time. The arc discharge is detected and an arc control signal 60 is transmitted to the energy circuit 28, triggering discharge of the stored energy to the electrode 30. The stored energy can be transmitted to the electrode 30 along a variety of different paths. The voltage of the stored energy is typically increased by an energy transformer 70 before being transmitted to the electrode 30.
摘要:
An electrode for an ignition device is made from a dilute nickel alloy which has improved resistance to high temperature oxidation, sulfidation, corrosive wear, deformation and fracture and 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 of the alloy may also be improved by the addition of hafnium to the alloy 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. These electrode alloys of the may also include at least one of cobalt, niobium, vanadium, molybdenum, tungsten, copper, iron, carbon, calcium, phosphorus or sulfur as trace elements, generally with specified maximum amounts. The ignition device may be a spark plug which includes a ceramic insulator, a conductive shell, center electrode and ground electrode. The center electrode, ground electrode, or both, may be made from the dilute nickel alloy of the invention. These electrodes may also include a core with thermal conductivity greater than that of the dilute nickel alloy, such as copper or silver or their alloys.
摘要:
An electrode for a spark ignition device, including a spark plug, which includes an alloy consisting essentially of, in weight percent, at least 15% Ni and the balance substantially Pt, and more particularly 15-45% Ni and the balance substantially Pt; 5-35% W, and the balance substantially Pd; and 5-15% Ni, 5-15% Pt, less than 10% Ir, and the balance substantially Pd.
摘要:
An electrode for an ignition device is made from a dilute nickel alloy which has improved resistance to high temperature oxidation, sulfidation, corrosive wear, deformation and fracture and 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 of the alloy may also be improved by the addition of hafnium to the alloy 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. These electrode alloys of the may also include at least one of cobalt, niobium, vanadium, molybdenum, tungsten, copper, iron, carbon, calcium, phosphorus or sulfur as trace elements, generally with specified maximum amounts. The ignition device may be a spark plug which includes a ceramic insulator, a conductive shell, center electrode and ground electrode. The center electrode, ground electrode, or both, may be made from the dilute nickel alloy of the invention. These electrodes may also include a core with thermal conductivity greater than that of the dilute nickel alloy, such as copper or silver or their alloys.