EP 1837964 A2 20070926 - Spark plug for use in an internal-combustion engine
Title (en)
Spark plug for use in an internal-combustion engine
Title (de)
Zündkerze für einen Verbrennungsmotor
Title (fr)
Bougie d'allumage à utiliser dans un moteur à combustion interne
Publication
Application
Priority
JP 2006075806 A 20060320
Abstract (en)
A spark plug 100 is comprised of a metal shell 1, an insulator 2, a center electrode 3 and a ground electrode 4. A rear-end face of the ground electrode 4 is welded to a front-end face of the metal shell 1, and a bent portion 5 located at the intermediated position in the longitudinal direction is bent toward the center of the spark plug 100. The ground electrode 4 assumes a circular-shape with a diameter of 2mm or less whereby an inflow of an air-fuel mixture is not disturbed even when the air-fuel mixture directly flows into a back face of the ground electrode 4. The ground electrode 4 is comprised of an outer layer 4A made of a nickel alloy and an inner layer 4B made of pure copper with an excellent thermal conductivity, in which a ratio of a cross-sectional area of the inner layer 4B to the entire cross-sectional area of the ground electrode 4 is 10% or more to 35% or less. Thus, the spark plug 100 which is excellent in heat sinking ability and can prevent a spring back phenomenon due to a difference in a coefficient of thermal expansion.
IPC 8 full level
H01T 13/32 (2006.01); H01T 13/39 (2006.01)
CPC (source: EP)
H01T 13/32 (2013.01); H01T 13/39 (2013.01)
Citation (applicant)
US 5210457 A 19930511 - OSHIMA TAKAFUMI [JP], et al
Designated contracting state (EPC)
DE FR
Designated extension state (EPC)
AL BA HR MK RS
DOCDB simple family (publication)
EP 1837964 A2 20070926; EP 1837964 A3 20130116; EP 1837964 B1 20140212; CN 101043125 A 20070926; CN 101043125 B 20120523
DOCDB simple family (application)
EP 07251139 A 20070319; CN 200710088227 A 20070320