Ignition apparatus

An ignition apparatus for an internal combustion engine which is equipped with an ignition coil including a primary coil and a secondary coil and a spark plug connected to the secondary coil and works to input energy to said spark plug using electromagnetic induction resulting from energization and deenergization of the primary coil to produce a discharge of a spark, comprising:

• a first circuit which energizes or deenergizes said primary coil to initiate a discharge of a spark in said spark plug;
• a second circuit which produces a flow of current through said primary coil in a direction opposite a direction in which a flow of current through said primary coil was produced by the first circuit during the discharge of the spark initiated by the first circuit, thereby keeping a flow of current through the secondary coil in the same direction as when a flow of current through the secondary coil was initiated by the first circuit, to continue a discharge of sparks;
• and
• a control portion which controls and operation of the second circuit,
• wherein the control portion calculates a target value of an energy input amount of energy inputted into the spark plug based on an in-cylinder flow velocity (v) that is a rate of flow in a cylinder of the internal combustion engine, a cylinder pressure in the cylinder of the internal combustion engine, and an air-fuel ratio, the control portion also calculating a command value of a secondary current that is a flow of current through the secondary coil based on the in-cylinder flow velocity, and
• wherein the control portion controls the operation of the second circuit using the target value of the energy input amount and the command value of the secondary current.