| 摘要 |
PURPOSE:To obtain a sufficient noise preventing effect and reduce a loss of ignition energy by specifying a material for a rotor electrode and a length of a discharge gap between the rotor electrode and an electrode secured at sides. CONSTITUTION:A spark discharge ignition portion at least, of a rotor electrode 3 is composed either of metallic aluminum or of aluminum alloy, and a length of a discharge gap G between the rotor electrode 3 and an electrode fixed at sides is instituted to be within an extent of 1.2-6.5mm. Further, at the time of a spark ignition, they are connected to make the rotor electrode 3 as a negative elecrode. |
