Ignition apparatus

Patent metadata

Field	Value
Publication number	US-10629368-B2
Application number	US-201816029203-A
Country	US
Kind code	B2
Filing date	Jul 6, 2018
Priority date	Apr 6, 2018
Publication date	Apr 21, 2020
Grant date	Apr 21, 2020

Abstract

A current flowing in a sub-primary coil can be limited in an ignition apparatus in which a voltage, generated in a secondary coil at a timing when a current in a main primary coil is cut off, generates a secondary current, and then the sub-primary coil is energized so that a superimposition current is generated in the secondary coil and in which a sub-IC connected in series with the sub-primary coil is pulse-controlled so that a current flowing in the sub-primary coil is controlled and hence the superimposition current is controlled.

First claim

What is claimed is:

1. An ignition apparatus comprising:
a main primary coil that generates positive-direction energization magnetic flux when energized by a power source and generates opposite-direction de-energization magnetic flux when de-energized;
a main switching device that is connected with the main primary coil and performs switching between energization and de-energization of the main primary coil;
a sub-primary coil that generates magnetic flux having a direction the same as that of the de-energization magnetic flux when energized by the power source;
a sub-switching device that is connected with the sub-primary coil and performs switching between energization and de-energization of the sub-primary coil; and
a secondary coil whose one terminal is connected with an ignition plug and that is magnetically coupled with the main primary coil and the sub-primary coil so as to generate discharge energy,
wherein a voltage generated in the secondary coil at a timing when the main switching device is de-energized generates a secondary current; then, the sub-switching device is energized and hence the sub-primary coil is energized so that a superimposition current is generated in the secondary coil and a current flowing in the sub-primary coil is limited,
wherein a first terminal of the sub-primary coil is connected to the power source and a second terminal of the sub-primary coil is connected to the sub-switching device, and
wherein a gate voltage of the sub-switching device is controlled based on detection of the current flowing in the sub-primary coil.

2. The ignition apparatus according to claim 1 , wherein the current flowing in the sub-primary coil is limited by increasing a voltage between a collector and an emitter of the sub-switching device.

3. The ignition apparatus according to claim 2 , wherein the voltage between the collector and the emitter of the sub-switching device is variable.

4. The ignition apparatus according to claim 3 , wherein in a normal state where the voltage of the power source or a voltage to be applied to the ignition plug does not change, the current that flows in the sub-primary coil is set to be unlimited.

5. The ignition apparatus according to claim 2 , wherein the limit value of the current that flows in the sub-primary coil is set to 10 A through 20 A.

6. The ignition apparatus according to claim 1 , wherein a current limiting resistor is inserted into a path in which only the current flowing in the sub-primary coil flows.

7. The ignition apparatus according to claim 6 , wherein the current limiting resistor is formed of a variable resistor.

8. The ignition apparatus according to claim 7 , wherein in a normal state where the voltage of the power source or a voltage to be applied to the ignition plug does not change, the current that flows in the sub-primary coil is set to be unlimited.

9. The ignition apparatus according to claim 1 , wherein a limit value of the current that flows in the sub-primary coil is set to 10 A through 20 A.

10. An ignition apparatus comprising:
a main primary coil that generates positive-direction energization magnetic flux when energized by a power source and generates opposite-direction de-energization magnetic flux when de-energized;
a main switching device that is connected with the main primary coil and performs switching between energization and de-energization of the main primary coil;
a sub-primary coil that generates magnetic flux having a direction the same as that of the de-energization magnetic flux when energized by the power source;
a sub-switching device that is connected with the sub-primary coil and performs switching between energization and de-energization of the sub-primary coil;
a current limiting resistor having a first terminal connected to a first terminal of the sub-primary coil; and
a secondary coil whose one terminal is connected with an ignition plug and that is magnetically coupled with the main primary coil and the sub-primary coil so as to generate discharge energy,
wherein a voltage generated in the secondary coil at a timing when the main switching device is de-energized generates a secondary current; then, the sub-switching device is energized and hence the sub-primary coil is energized so that a superimposition current is generated in the secondary coil and a current flowing in the sub-primary coil is limited by the current limiting resistor,
wherein a second terminal of the sub-primary coil is connected to the power source and a second terminal of the current limiting resistor is connected to the sub-switching device.

11. An ignition apparatus comprising:
a main primary coil that generates positive-direction energization magnetic flux when energized by a power source and generates opposite-direction de-energization magnetic flux when de-energized;
a main switching device that is connected with the main primary coil and performs switching between energization and de-energization of the main primary coil;
a sub-primary coil that generates magnetic flux having a direction the same as that of the de-energization magnetic flux when energized by the power source;
a sub-switching device that is connected with the sub-primary coil and performs switching between energization and de-energization of the sub-primary coil; and
a secondary coil whose one terminal is connected with an ignition plug and that is magnetically coupled with the main primary coil and the sub-primary coil so as to generate discharge energy,
wherein a voltage generated in the secondary coil at a timing when the main switching device is de-energized generates a secondary current; then, the sub-switching device is energized and hence the sub-primary coil is energized so that a superimposition current is generated in the secondary coil, and
wherein a current flowing in the sub-primary coil is limited by increasing a voltage between a collector and an emitter of the sub-switching device.

12. The ignition apparatus according to claim 11 , wherein the voltage between the collector and the emitter of the sub-switching device is variable.

13. The ignition apparatus according to claim 12 , wherein in a normal state where the voltage of the power source or a voltage to be applied to the ignition plug does not change, the current that flows in the sub-primary coil is set to be unlimited.

14. The ignition apparatus according to claim 11 , wherein a limit value of the current that flows in the sub-primary coil is set to 10 A through 20 A.

Assignees

• Mitsubishi Electric Corp

Inventors

• Idogawa Takashi
• Kataoka Naoki
• Muramoto Yuichi

Classifications

• H01F38/12 Primary

  Ignition, e.g. for IC engines · CPC title

• F02P3/02

  having inductive energy storage, e.g. arrangements of induction coils {(ignition coils structurally combined with sparking plugs F02P13/00; constructional details of ignition coils H01F38/12)} · 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

• F02P9/002

  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

• F02D37/02

  one of the functions being ignition · CPC title