摘要 |
PROBLEM TO BE SOLVED: To provide an ignition plug for a gas engine superior in ignition efficiency and durability. SOLUTION: This ignition plug for gas engine is disposed for a sub combustion chamber of a sub chamber type lean combustion gas engine equipped with the sub combustion chamber communicating with a main combustion chamber. A center electrode 1 of a center electrode body Ec and a ground electrode 2 of a ground electrode body Eg disposed to confront to each other in an interval are formed by a material mainly consisting of iridium. A groove 1A is formed in a recessed condition on a confronting ground electrode surface 1a of the central electrode 1 confronting the ground electrode 2. When a diameter of the center electrode 1 is D1, a diameter of a ground electrode 2 is D2, a width of the groove 1A is W, and a depth of the groove 1A is H, the center electrode 1 and the ground electrode 2 are constituted to satisfy following expressions; D1>1.5 mm, D1÷15<W<D1÷5, H>D1÷5, and D2>0.9×D1.
|