SPARK PLUG

• Main Authors: SHIBATA TSUTOMU, SUMOYAMA DAISUKE, TANAKA TOMOO
• Format: Patent
• Language: English
• Published: 22.12.2011
• Subjects: ALLOYS; BASIC ELECTRIC ELEMENTS; CHEMISTRY; CORONA DEVICES; ELECTRICITY; FERROUS OR NON-FERROUS ALLOYS; GENERATING IONS TO BE INTRODUCED INTO NON-ENCLOSED GASES; METALLURGY; OVERVOLTAGE ARRESTERS USING SPARK GAPS; SPARK GAPS; SPARKING PLUGS; TREATMENT OF ALLOYS OR NON-FERROUS METALS

PROBLEM TO BE SOLVED: To provide a spark plug with a noble metal chip exhibiting desired durability, more specifically, a spark plug with a noble metal chip exhibiting excellent wear resistance, peeling resistance and chipping resistance.SOLUTION: The spark plug (1) contains Mp(Mp is Pt, or an element group consisting of Pt and Pd, where Pd is 20 mass% or less for the mass of a noble metal chip), Cu, and M(M is at least one kind selected from an element group consisting of Rh, Ir, Ru, Re and W) by 95 mass% or more in total, where the mass ratio of the Mp, Cu and M falls within a specific range, or (2) the mass ratio (Mp, Cu, M) of the Mp, Cu and M falls within a specific range, and the welding area S(mm), the protrusion dimension of a chip H(mm), the covering dimension L(mm), and the distance between the chip and a welded part h(mm) satisfy following conditions; (a)H≤0.13S+1.18, (b)S≤5, (c)0.1≤h, or 0.03≤L.