Ignition device

Patent metadata

Field	Value
Publication number	US-2016164263-A1
Application number	US-201514668337-A
Country	US
Kind code	A1
Filing date	Mar 25, 2015
Priority date	Dec 4, 2014
Publication date	Jun 9, 2016
Grant date	—

Abstract

In an ignition device, at a timing of a control signal provided by a control device to control an ignition coil device or at a timing prior to the control signal in order that a high voltage is applied to an ignition plug to initiate a spark discharge, a control circuit of an AC power source unit in response to the control signal controls switching elements composing a bridge circuit in the AC power source unit for a DC-AC inversion to thereby short-circuit a winding of a transformer device on the side of the AC power source unit, connected between a boosting device including a capacitor device and the bridge circuit for the circulation of a capacitance discharging current from the boosting device to the transformer device.

First claim

What is claimed is:

1 . An ignition device comprising:
an ignition plug that ignites a combustible gas mixture in a combustion chamber of an internal combustion engine; an ignition coil device that applies a DC (Direct Current) high voltage to the ignition plug to initiate a spark discharge; an AC (Alternating Current) power source unit that generates an AC current to be inputted to a path of the spark discharge; a boosting device, composed of a capacitor device and an inductor device, that boosts the AC current outputted from the AC power source unit and supplies the AC current boosted to the ignition plug; and a control device that controls operations of the ignition coil device and the AC power source unit; wherein the AC power source unit includes a bridge circuit for a DC-AC inversion composed of a plurality of switching elements, a transformer device connected between the boosting device and the bridge circuit, and a control circuit that controls the switching elements at a timing of a control signal from the control device to control the ignition coil device or at a timing prior to the control signal in order that a high voltage is applied to the ignition plug to initiate the spark discharge, to thereby short-circuit a winding of the transformer device on a side of the AC power source unit.

2 . The ignition device according to claim 1 , wherein
the bridge circuit comprises a full bridge circuit having a first and a second pair of switching elements respectively connected in series between a terminal of a high voltage side and a terminal of a low voltage side of a DC voltage source, in which the winding of the transformer device on the side of the AC power source unit is connected between a connection point of the first pair of switching elements and a connection point of the second pair of switching elements, and the control circuit controls, at the timing of the control signal or at the timing prior to the control signal, the first and the second pair of switching elements on the high voltage side to an ON state and controls the first and the second pair of switching elements on the low voltage side to an OFF state, or controls, at the timing of the control signal or at the timing prior to the control signal, the first and the second pair of switching elements on the low voltage side to an ON state and controls the first and the second pair of switching elements on the high voltage side to an OFF state.

3 . The ignition device according to claim 1 , wherein
the bridge circuit comprises a half bridge circuit having a pair of switching elements connected in series between a terminal of a high voltage side and a terminal of a low voltage side of a DC voltage source, in which the winding of the transformer device on the side of the AC power source unit is connected between a connection point of the pair of switching elements and the terminal of the low voltage side, and the control circuit controls, at the timing of the control signal or at the timing prior to the control signal, the pair of switching elements on the low voltage side to an ON state and controls the pair of switching elements on the high voltage side to an OFF state.

4 . The ignition device according to claim 2 , wherein the low voltage side is ground.

5 . The ignition device according to claim 3 , wherein the low voltage side is ground.

6 . The ignition device according to claim 1 , wherein the control circuit controls the switching elements to the ON state during at least 2 microseconds from that timing.

7 . The ignition device according to claim 2 , wherein the control circuit controls the switching elements to the ON state during at least 2 microseconds from that timing.

8 . The ignition device according to claim 3 , wherein the control circuit controls the switching elements to the ON state during at least 2 microseconds from that timing.

9 . The ignition device according to claim 1 , wherein the control circuit controls the switching elements to the ON state immediately after or in a lapse of a predetermined time after the AC power source unit has finished the DC-AC inversion to thereby short-circuit the winding of the transformer device on the side of the AC power source unit.

10 . The ignition device according to claim 2 , wherein the control circuit controls the switching elements to the ON state immediately after or in a lapse of a predetermined time after the AC power source unit has finished the DC-AC inversion to thereby short-circuit the winding of the transformer device on the side of the AC power source unit.

11 . The ignition device according to claim 3 , wherein the control circuit controls the switching elements to the ON state immediately after or in a lapse of a predetermined time after the AC power source unit has finished the DC-AC inversion to thereby short-circuit the winding of the transformer device on the side of the AC power source unit.

12 . The ignition device according to claim 1 , wherein the control circuit controls the bridge circuit so that the AC power source unit does not restart the DC-AC inversion until a time obtained from a prestored memory map composed of at least one of a predetermined time and a rotational speed or a load of the internal combustion engine elapses from that timing.

13 . The ignition device according to claim 2 , wherein the control circuit controls the bridge circuit so that the AC power source unit does not restart the DC-AC inversion until a time obtained from a prestored memory map composed of at least one of a predetermined time and a rotational speed or a load of the internal combustion engine elapses from that timing.

14 . The ignition device according to claim 3 , wherein the control circuit controls the bridge circuit so that the AC power source unit does not restart the DC-AC inversion until a time obtained from a prestored memory map composed of at least one of a predetermined time and a rotational speed or a load of the internal combustion engine elapses from that timing.

Assignees

• Mitsubishi Electric Corp

Inventors

• Muramoto Yuichi
• Tanaya Kimihiko

Classifications

• F02P5/145

  using electrical means · CPC title

• H01T15/00 Primary

  Circuits specially adapted for spark gaps, e.g. ignition circuits (ignition circuits for internal-combustion engines F02P; electric spark ignition for combustion apparatus F23Q; protection circuits using spark gaps H02H9/06) · CPC title

• F02P3/04

  Layout of circuits · CPC title

• F02P15/10

  having continuous electric sparks · CPC title

• F02P11/00

  Safety means for electric spark ignition, not otherwise provided for · CPC title