Spark ignition engine, controller for use in the engine, ignition coil for use in the engine
View Patent ↗An engine generating two or more ignition sparks by the same spark plug, which can avoid a torque reduction caused by misfire of main ignition, can start firing and burning at proper timing depending on operating conditions, and can reduce misfires. A novel controller and a novel ignition coil adapted for realizing that engine are also provided. One spark plug and at least one ignition coil are provided per cylinder. When performing a plurality of ignitions during the compression stroke in the cylinder, before main ignition to start firing and burning at proper timing depending on operating conditions of the engine, preliminary pre-ignition is performed to form a fire seed around the spark plug. The main ignition is then performed to cause main burning. Misfire is avoided, appropriate torque can be generated, and combustion stability can be improved.
1. An ignition coil for use in the spark ignition engine comprising one spark plug and a plurality of ignition coils per cylinder assembled into a single unit and performing a plurality of ignitions during a compression stroke of each cylinder, wherein main ignition is performed at main ignition timing decided depending on the operating conditions of said engine, at least one preliminary pre-ignition is performed before the main ignition on of said ignition coils outputs energy for the main ignition and another of said ignition coils energy for the preliminary pre-ignition, wherein one of said plurality of ignition coils is constituted as a cylindrical ignition coil inserted in a plug hole, and another is constituted as a horizontally oriented ignition coil mounted on said cylindrical ignition coil and has a second center core arranged in a direction to cross a first center core of said cylindrical ignition coil.
2. An ignition coil for use in the spark ignition engine according to claim 1 , wherein said cylindrical ignition coil and said horizontally oriented ignition coil are accommodated in one housing, and a connector having terminals for supply of electric power to said two coils is integrally mounted to said housing.