Ignition control apparatus

Patent metadata

Field	Value
Publication number	US-10161376-B2
Application number	US-201414893740-A
Country	US
Kind code	B2
Filing date	May 20, 2014
Priority date	May 24, 2013
Publication date	Dec 25, 2018
Grant date	Dec 25, 2018

Abstract

An ignition control apparatus for engines is provided. The ignition control apparatus is designed to control a switch to release energy stored in a capacitor during spark discharge, thereby supplying a primary current to an other end side opposite a one end of a primary winding of an ignition coil connected to a dc power supply. This provides the ignition control apparatus which is capable of minimizing an increase in size or manufacturing cost and stabilizing the state of combustion of an air-fuel mixture.

First claim

The invention claimed is:

1. An ignition control apparatus engineered to control operation of a spark plug provided to ignite an air-fuel mixture within a cylinder of an internal combustion engine, comprising:
an ignition coil which is equipped with a primary winding and a secondary winding and designed so that a primary current that is an electric current flowing through said primary winding is increased or decreased to develop a secondary current in said secondary winding connected to said spark plug;
a dc power supply with a non-grounding output terminal connected to an end of said primary winding to have said primary current flow through said primary winding;
a first switching device that is a semiconductor switching device which is equipped with a first control terminal, a first power supply terminal, and a first grounding terminal and works to establish or block electric communication between said first power supply terminal and said first grounding terminal based on a first control signal inputted to said first control terminal, said first power supply terminal being connected to an other end of said primary winding, said first grounding terminal being connected to a ground side;
a second switching device that is a semiconductor switching device which is equipped with a second control terminal, a second power supply terminal, and a second grounding terminal and works to establish or block electric communication between said second power supply terminal and said second grounding terminal based on a second control signal inputted to said second control terminal, said second grounding terminal being connected to said other end of said primary winding,
a third switching device that is a semiconductor switching device which is equipped with a third control terminal, a third power supply terminal, and a third grounding terminal and works to establish or block electric communication between said third power supply terminal and said third grounding terminal based on a third control signal inputted to said third control terminal, said third power supply terminal being connected to said second power supply terminal of said second switching device, said third grounding terminal being connected to said ground side;
an energy storage coil that is an inductor disposed in a power line connecting between said non-grounding output terminal of said dc power supply and said third power supply terminal of said third switching device, said energy storage coil working to store energy when said third switching device is turned on and discharge the energy when said third switching device is turned off;
a capacitor which is connected in series with said energy storage coil between said non-grounding output terminal of said dc power supply and said ground side, said capacitor working to store the energy released from said energy storage coil when said third switching device is turned off; and
a controlling portion is programmed to:
control the second switching device and said third switching device,
turn off said third switching device and turn on said second switching device during discharge of a spark from said spark plug, as initiated upon turning off of said first switching device, to release the energy from said capacitor which is in turn supplied to said primary winding through said other end, thereby cause said primary current to flow through said primary winding, and
variably set a duty factor of said second control signal.

2. An ignition control apparatus as set forth in claim 1 , wherein said controlling portion is programmed to set said duty factor as a function of a running condition of said internal combustion engine.

3. An ignition control apparatus as set forth in claim 2 , wherein said running condition of said internal combustion engine contains at least an engine speed.

4. An ignition control apparatus as set forth in claim 1 , wherein said controlling portion is further programmed to variably set said duty cycle in one combustion cycle.

5. An ignition control apparatus as set forth in claim 4 , wherein said controlling portion is further programmed to increase said duty factor with time.

6. An ignition control apparatus as set forth in claim 5 , wherein said controlling portion is further programmed to variably set a rate of increase in said duty factor with time.

7. An ignition control apparatus for igniting an internal combustion engine which at lease comprises:
a dc power supply;
a step-up circuit which steps up a power supply voltage at said dc power supply;
an ignition coil which develops a high secondary voltage at a secondary winding by an increase or a decrease in current flowing in the primary winding connected to said step-up circuit;
an ignition switching device which switches between supply and cutoff of current to said primary winding;
a spark plug which is connected to said secondary winding and produces a spark discharge upon application of secondary voltage from said secondary winding, and
an auxiliary power supply which additionally performs ignition switching device discharge from said step-up circuit and stop the ignition switching device discharge after said spark plug is started by opening or closing of said ignition switching device to discharge the spark plug, thereby increasing current flowing through said secondary winding,
wherein said auxiliary power supply is equipped with an auxiliary switching device which switches between input of energy from said auxiliary power supply and stop thereof, said auxiliary switching device includes a soft-off circuit which is configured to set a turning off speed to be slower than a turning on speed, and
wherein the input of energy from said auxiliary power supply is applied to said primary winding from a low voltage side thereof.

8. An ignition control apparatus as set forth in claim 7 , further comprising an auxiliary device driver configured to open or close said auxiliary switching device one time or a plurality of times according to a discharge duration signal which instructs to start and stop the input of energy from said auxiliary power supply.

9. An ignition control apparatus as set forth in claim 7 , wherein said soft-off circuit includes one or a plurality of soft-off capacitors connected between a gate and a source of said auxiliary switching device.

10. An ignition control apparatus as set forth in claim 7 , wherein said soft-off circuit is a driver and is configured to slowly decrease a drive voltage for driving said auxiliary switching device.

11. An ignition control apparatus as set forth in claim 7 , wherein said step-up circuit is made up of an energy storage inductor which is connected to said dc power supply, a switching device which switches between supply and cut of current to said inductor in a given cycle only for a given period of time according to said ignition signal, a capacitor which is connected in parallel to said inductor, and a first rectifying device which rectifies current from said inductor to said capacitor.

12. An ignition control apparatus as set forth in claim 11 , wherein said auxiliary power supply is made up of an auxiliary switching device which is disposed between said capacitor and said primary winding and configured to switch between discharge from said capacitor and stop of the discharge from said capacitor, a second rectifying device which rectifies current from said capacitor to said primary winding, said dc power supply, said inductor, and said capacitor.

13. An ignition control apparatus for igniting an internal combustion engine which at lease comprises:
a dc power supply;
a step-up circuit which steps up a power supply voltage at said

Assignees

• Denso Corp

Inventors

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

Classifications

• F02P3/0892

  using digital techniques · CPC title

• F02P5/145

  using electrical means · CPC title

• 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

• F02P3/0435

  with semiconductor devices (F02P3/0453, F02P3/051, F02P3/0552 take precedence) · CPC title

• F02P7/03

  with electrical means (ignition occurring simultaneously at different places in one engine cylinder or in two or more separate engine cylinders F02P15/08) · CPC title