An electromagnetic wave oscillation device includes: a buck-boost circuit having buck-boosters and switching elements; an electromagnetic wave oscillator; an amplifier to amplify an electromagnetic wave and supply an amplified electromagnetic wave to a resistive part; a detector to detect a reflected wave from the resistive part; and a controller to send to one of the switching elements an operation signal in predetermined order, synchronizing with an oscillation timing of the electromagnetic wave oscillator, to output a current from the corresponding buck-boosters to the amplifier in a non-smooth manner. When a detected value of the reflected wave exceeds a predetermined value upon said current output by operating the one of the switching elements, the controller stops sending the operation signal to one or more of the other switching elements that are supposed to output the current after said current output by operating the one of the switching elements.

An ignition device for engine according to the present invention performs continuous spark discharge of an ignition plug by using a multiplex signal, an integration signal or a control signal. In the multiplex signal, discharge continuous signals IGW#1 to 4 for cylinders of the engine have been multiplexed. In the integration signal, a discharge continuous signal IGW and a secondary current instruction signal IGA have been added to an ignition signal IGT. In the control signal, the secondary current instruction signal IGA has been added into the multiplex signal or the integration signal. This structure can reduce the total number of signal lines connected between an ECU and a controller, and further reduce a signal line to transmit the secondary current instruction signal IGA.

An ignition apparatus for an internal-combustion engine includes a main ignition CDI circuit that has a main ignition boosting circuit boosting battery voltage and a main ignition capacitor storing electric charge boosted by the main ignition boosting circuit, and that releases the electric charge stored in the main ignition capacitor to a primary coil of an ignition coil to make an ignition plug generate spark discharge, and an energy input circuit that has an energy input boosting circuit boosting battery voltage and an energy input capacitor storing electric charge boosted by the energy input boosting circuit, and that releases the electric charge stored in the energy input capacitor to the primary coil, during a spark discharge started by operation of the main ignition CDI circuit, to make a secondary current flow in the same direction and to a secondary coil of the ignition coil, thereby making spark discharge continue which is started by the operation of the main ignition CDI circuit.

An ignition device at least equipped with a DC power source, an ignition coil unit, a spark plug, an ignition switch, and an auxiliary power source, wherein the auxiliary power source is at least equipped with a discharge energy accumulating means, a discharge switch, and a discharge driver. The ignition device is further equipped with a secondary-current feedback controlling means comprising a secondary current detecting means for detecting a secondary current flowing during the ignition coil unit discharge period, and a secondary current feedback control circuit-for determining an upper limit and a lower limit for the secondary current from binary threshold values, and driving so as to open and close the discharge switch on the basis of the determination results. Furthermore, energy is introduced from the auxiliary power source without switching the polarity of the secondary current.

A discharge control unit causes a high voltage to be generated in a secondary coil by controlling an igniter unit so as to block a flow of current from a primary coil towards a ground side, and controls a spark plug so that electric discharge is formed between electrodes of the spark plug. An energy input control unit controls an energy input unit to input electrical energy to an ignition coil after start of control of the spark plug by the discharge control unit. A normal ignition control unit controls ignition of an air-fuel mixture in a combustion chamber only through control of the spark plug by the discharge control unit. A specific ignition control unit controls the ignition of the air-fuel mixture in the combustion chamber through control of the spark plug by the discharge control unit and through control of the energy input unit by the energy input control unit. A control unit performs ignition control by the specific ignition control unit until a first predetermined period elapses after a start-up condition of an engine is established, and switches to ignition control by the normal ignition control unit after the elapse of the first predetermined period.

Provided are an ignition apparatus and an ignition control method capable of suppressing occurrence of a defect caused by a charge unit, which may occur when ignition of a combustible mixture in a combustion chamber of an internal combustion engine needs to be stopped. When a stop condition for stopping ignition of a combustible mixture in a combustion chamber (2) of an internal combustion engine (1) is satisfied, supply of plasma generation energy to an ignition plug (3) is stopped, and DC energy charged in a charge unit (42) is discharged.

An ignition apparatus performs energy input control in which energy is continuously inputted to an ignition coil to enable a spark discharge in a predetermined energy input period after interrupting a primary current by an ignition switch and generating a discharge of a spark plug by a secondary current. A combustion state determination circuit determines a combustion state by comparing a combustion pressure P detected by a combustion state detector. When the combustion pressure P is smaller than a second threshold Pth2, and there is room for improving the combustion state with respect to the present energy input condition, the energy input period IGW is increased or a target secondary current I2* is increased. By compensating the condition of the energy input control in accordance with the combustion state, a target combustion state can be achieved with just enough energy consumption.

A discharge control unit causes a high voltage to be generated in a secondary coil by controlling an igniter unit so as to block a flow of current from a primary coil towards a ground side, and controls a spark plug so that electric discharge is formed between electrodes of the spark plug. An energy input control unit controls an energy input unit to input electrical energy to an ignition coil after start of control of the spark plug by the discharge control unit. A normal ignition control unit controls ignition of an air-fuel mixture in a combustion chamber only through control of the spark plug by the discharge control unit. A specific ignition control unit controls the ignition of the air-fuel mixture in the combustion chamber through control of the spark plug by the discharge control unit and through control of the energy input unit by the energy input control unit. A control unit performs ignition control by the specific ignition control unit until a first predetermined period elapses after a start-up condition of an engine is established, and switches to ignition control by the normal ignition control unit after the elapse of the first predetermined period.

A maximum value of a discharge current from a capacitor 13, detected by a primary-side current detection means 24 disposed at a grounded end of the capacitor 13, is controlled such as not to exceed a predetermined first control value Y1. The first control value Y1 is derived based on magnetic saturation of a primary winding 3, with the control being performed by controlling the on-off state of an energy injection switching means 20. As a result, magnetic saturation of the primary winding 3 can be prevented, and the reliability of an ignition apparatus which incorporates an energy injection circuit 6 can be increased.

An ignition device at least equipped with a DC power source, an ignition coil unit, a spark plug, an ignition switch, and an auxiliary power source, wherein the auxiliary power source is at least equipped with a discharge energy accumulating means, a discharge switch, and a discharge driver. The ignition device is further equipped with a secondary-current feedback controlling means comprising a secondary current detecting means for detecting a secondary current flowing during the ignition coil unit discharge period, and a secondary current feedback control circuit-for determining an upper limit and a lower limit for the secondary current from binary threshold values, and driving so as to open and close the discharge switch on the basis of the determination results. Furthermore, energy is introduced from the auxiliary power source without switching the polarity of the secondary current.