Denso Corporation

So-ken Corporation

Shohei Ishida

Shunichi Takeda

Fumiaki Aoki

Noriaki Nishio

Yuya Abe

Kazuaki Ueda

Hideaki Kosuge

Shun Sugita

An ignition apparatus for internal combustion engines is provided. The ignition apparatus is equipped with an ECU. The ECU monitors a path length of a discharge of a spark for a period of time in which a second circuit delivers or inputs energy in the form of a threshold value determination. When the path length has become too short, the ECU determines that ignition is expected to be delayed and then selects a special mode to control the delay of the ignition. The ECU increase a target value of an energy input amount. This enables the delay of ignition resulting from a short extension of the path length to be minimized. The ignition apparatus equipped with the second circuit to continue the discharge of sparks is, thus, capable of reducing a variation in ignition without the need for uniformly increasing the energy input amount.

Ignition apparatus having circuit to continue spark discharge in an internal combustion engine

A spark plug includes a main ground electrode having a main connecting portion connected to the housing and forming a discharge gap between the main ground electrode and the center electrode, and a sub ground electrode having a sub connecting portion connected to the housing. The direction on which the main connecting portion and a plug center axis are arranged is set to be perpendicular to an air flow direction of an air stream in the combustion chamber. The sub connecting portion is located in a downstream side than the main connecting portion. The tip end position of the sub ground electrode in the plug axial direction is located in farther tip end side than that of the main ground electrode is. The sub ground electrode is configured such that an end point of the discharge spark is movable on the sub ground electrode.

Spark plug for internal combustion engine

In an ignition device, a second circuit energizes a primary coil from its negative side in a first direction to thereby maintain energization of a second coil in a second direction during spark discharge started by a first circuit. The maintained energization continuously supplies energy to a spark plug, thus performing a continuation of the spark discharge. The first direction is opposite to a direction of energization of the primary coil carried out by the first circuit, and the second direction is the same as a direction of energization of the second coil that has been started based on the first circuit. A humidity detection unit detects humidity of intake air into an engine. The control section controls the first circuit to advance start timing of the spark discharge generated by the first circuit in accordance with an increase in the humidity of the intake air.

Ignition device

Growing community of inventors

Nishio, Japan

Shohei Ishida