Ignition control device

Patent metadata

Field	Value
Publication number	US-9822753-B2
Application number	US-201414903897-A
Country	US
Kind code	B2
Filing date	Jul 4, 2014
Priority date	Jul 11, 2013
Publication date	Nov 21, 2017
Grant date	Nov 21, 2017

Abstract

An ignition control device includes a control unit to control first to third switching elements so that during ignition discharge, which is started by turning off the first switching element, energy stored on a capacitor is discharged by turning off the third switching element and turning on the second switching element for supplying a primary current to an end of a primary winding opposite to an end thereof connected to a direct-current power supply. During inductive discharge of a spark plug, the control unit non-intermittently turns on the second switching element so that the second switching element is turned on over a successive energy input time period, according to the operating conditions of an internal combustion engine.

First claim

What is claimed is:

1. An ignition control device configured to control operation of a spark plug provided to ignite an air fuel mixture in a cylinder of an internal combustion engine, characterized in that the device comprises:
an ignition coil having a primary winding and a secondary winding and configured to generate a secondary current in the secondary winding connected to the spark plug by increasing/decreasing a primary current that is a current passing through the primary winding;
a direct-current power supply having a non-grounded side output terminal connected to one end of the primary winding so that the primary current is passed through the primary winding;
a first switching element that is a semiconductor switching element having a first control terminal, a first power supply side terminal, and a first grounded side terminal, the semiconductor switching element being configured to control turning on/off of a current across the first power supply side terminal and the first grounded side terminal on the basis of a first control signal inputted to the first control terminal, in which the first power supply side terminal is connected to another end of the primary winding and the first grounded side terminal is connected to ground;
a second switching element that is a semiconductor switching element having a second control terminal, a second power supply side terminal, and a second grounded side terminal, the semiconductor switching element being configured to control turning on/off of a current across the second power supply side terminal and the second grounded side terminal on the basis of a second control signal inputted to the second control terminal, in which the second grounded side terminal is connected to another end of the primary winding;
a third switching element that is a semiconductor switching element having a third control terminal, a third power supply side terminal, and a third grounded side terminal, the semiconductor switching element being configured to control turning on/off of a current across the third power supply side terminal and the third grounded side terminal on the basis of a third control signal inputted to the third control terminal, in which the third power supply side terminal is connected to the second power supply side terminal of the second switching element and the third grounded side terminal is connected to ground;
an energy storage coil that is an inductor interposed in an electric power line connecting the non-grounded side output terminal of the direct-current power supply to the third power supply side terminal of the third switching element, in which the energy storage coil is provided to store energy by turning on the third switching element;
a capacitor connected in series with the energy storage coil, being located at a position between the non-grounded side output terminal of the direct-current power supply and the ground, the capacitor being provided to store energy by turning off the third switching element; and
a control unit provided to control the second switching element so that during ignition discharge at the spark plug started by turning off the first switching element, the second switching element is non-intermittently turned on to cause the capacitor to discharge stored energy for supplying the primary current from the another end to the primary winding, wherein
during the ignition discharge, the control unit non-intermittently turns on the second switching element over an energy input time period.

2. The ignition control device according to claim 1 , characterized in that the control unit non-intermittently turns on the second switching element over the energy input time period so that the primary current supplied from the another end to the primary winding has a waveform that is changed in an arc shape.

3. The ignition control device according to claim 1 , characterized in that the device further comprises:
a primary voltage acquiring section provided to acquire a primary voltage that is a voltage applied to the primary winding, wherein
the control unit controls the second switching element on the basis of the primary voltage acquired by the primary voltage acquiring section.

Assignees

• Denso Corp

Inventors

• Ishitani Masahiro
• Sugiura Akimitsu
• Toriyama Makoto
• Nakayama Satoru
• KONDOU Yuuki

Classifications

• F02P9/002 Primary

  Control of spark intensity, intensifying, lengthening, suppression (by means of current control in the storage devices F02P3/05, F02P3/09, during starting F02P15/12) · CPC title

• F02P3/093

  Closing the discharge circuit of the storage capacitor with semiconductor devices · CPC title

• F02P3/0838

  with semiconductor devices (F02P3/0861, F02P3/0884, F02P3/093 take precedence) · CPC title

• F02P3/0846

  using digital techniques (F02P3/0869, F02P3/0892, F02P3/096 take precedence) · CPC title

• F02P9/007

  by supplementary electrical discharge in the pre-ionised electrode interspace of the sparking plug, e.g. plasma jet ignition · CPC title