The Performance of a Multigap Spark Plug Designed for Automotive Applications 760264
The electrical principle of operation, the geometrical and electrical circuit constraints on the design of, and the electrical and in-engine performance of a multigap spark plug developed for automotive applications are described.
The electrical principle of operation is based on successively breaking down an array of spark gaps through the use of a resistive ladder network.
The measurements evaluating the electrical performance of various multigap designs indicate that these plugs can deliver up to twice the energy of a single gap plug to the arcs, using the same ignition system. The increased amount of energy is also delivered in a shorter time than for single gap plugs.
The measurements evaluating the in-engine performance of these plugs further indicate that improvements of up to 6% in fuel economy for a simulated CVS test run, the extension of the lean misfire limit by several A/F ratio numbers under various engine operating conditions, and improvements in driveability can be achieved compared to the performance of standard plugs under the same operating conditions.