Aiming at the technique of variable value timing on automobile-engine, two bottleneck problems on the dynamic-effect and the control-object of inflammable gas-flow are analyzed, the derived control relation to variable phase angle is aquired, and the actual structure is discussed, and reference to study up on the technique is offered.

The spark plug is installed in the combustion chamber of the gasoline engine and used to ignite the compressed combustible mixture in the cylinder.