Denso Corporation

Keiko Miyake

Kanechiyo Terada

Takashi Ohno

Shunichi Takeda

Yasuo Kakumae

Tetsuya Miwa

An ignition device for an internal combustion engine includes: an ignition plug; a primary coil; a secondary coil magnetically linked to the primary coil and connected to the ignition plug; a main ignition circuit causing a spark discharge to occur in the ignition plug; an energy supply circuit that supplies and stops electrical energy to the predetermined winding of the primary coil to accordingly cause the spark discharge to continue; a recirculation circuit that permits and prohibits current recirculation through a recirculation path including the predetermined winding; and a controller configured to: control the main ignition circuit, and determine a start time of a permission of the current recirculation by the recirculation circuit using, as a trigger, the interruption signal which causes the main ignition circuit to interrupt the current through the primary coil, and end the permission after a predetermined time period has elapsed since the start time.

Ignition device for internal combustion engine

An internal combustion engine ignition device includes an ignition coil, an ignition plug, a main ignition circuit, and an energy input circuit. A first switching element of the main ignition circuit performs energization and interruption of energization to a first coil part of a primary coil to generate an induced electromotive force using a DC voltage. A second switching element of the energy input circuit performs energization and interruption of energization to a second coil part of the primary coil to keep a discharge current in a secondary coil within an intended range directly using the DC voltage, after the induced electromotive force has been generated. A soft-off circuit of the energy input circuit slows a turn-off speed of the second switching element. The energy input circuit is configured to, when decreasing a signal voltage added to a gate of the second switching element, execute a first decreasing stage of decreasing the signal voltage until it reaches the vicinity of a gate-source threshold voltage and a second decreasing stage of gradually decreasing the signal voltage in the vicinity of the threshold voltage.

Internal combustion engine ignition device

An ignition system includes a primary coil, a secondary coil, a first switch, a second switch, a third switch, a diode, and a switch control section. In the primary coil, a power supply is connected to a contact point between a first winding and a second winding. The secondary coil is magnetically coupled to the primary coil. The first switch is connected in series with the first winding. The second switch is connected in series with the second winding on the opposite side from the contact point. The third switch is connected in series with the second switch. The diode includes an anode connected between the second switch and the third switch and a cathode connected to the contact point. The switch control section controls opening and closing of each switch.

Ignition system

An ignition device includes: a primary coil including a first winding and a second winding connected in series to the first winding; a secondary coil connected to a spark plug and magnetically coupled to the primary coil; a first switch that opens or closes the electrical path between the first terminal and the ground; a second switch that opens or closes the electrical path between the power source and the second terminal; a third switch that opens or closes the electrical path between the power source and the connection point; a fourth switch that opens or closes the electrical path between the second terminal and the ground; and a switch control unit that controls the opening and closing of each switch to open or close each electrical path.

Ignition device

An ignition system includes a primary coil, a secondary coil, a first switch, a second switch, a third switch, a fourth switch, and a switch control section. The primary coil includes a first winding, and a second winding which is connected in series with the first winding. The secondary coil is connected to an ignition plug and is magnetically coupled to the primary coil. The first switch connects and disconnects an electrical path between a first terminal and a ground. The second switch connects and disconnects an electrical path between a power supply and a second terminal. The third switch connects and disconnects an electrical path between the power supply and the first terminal. The fourth switch connects and disconnects an electrical path between a contact point and the ground. The switch control section controls opening and closing of each switch to connect and disconnect the associated electrical path.

An ignition device for generating a spark discharge at a spark plug based on a first voltage from a first supply and a second voltage from a second supply. The second voltage is higher than the first voltage. In the ignition device, a primary coil includes a center tap, a first terminal on a ground side of the center tap, and a second terminal on a first-supply side of the center tap, and a secondary coil is electromagnetically coupled to the primary coil and electrically connected to the spark plug. A first switch is configured to make or break an electrical connection between the first terminal and ground, a second switch is configured to make or break an electrical connection between the second supply and the center tap, and a third switch is configured to pass or interrupt a current from the second terminal to the first supply. A controller is configured to control an on/off state of each of the first to third switches.

In an ignition apparatus, a controller outputs a discharge start signal instructing a start of a discharge in the spark plug, and a discharge control signal instructing control of a discharge current in the spark plug after the start of the discharge. A signal line connects between the controller and a control circuit. The discharge start signal and the discharge control signal are transferred from the controller to the control circuit via the signal line. The controller modulates, based on the plural command values, the discharge control signal such that the modulated discharge control signal includes information representing the plural command values and change timings for the respective command values. The control circuit controls, based on the discharge start signal and the modified discharge control signal, the energization circuit to thereby adjust the discharge current to each of the command values at a corresponding one of the change timings.

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Kariya, Japan

Keiko Miyake