Ignition control system

Patent metadata

Field	Value
Publication number	US-10508637-B2
Application number	US-201715668791-A
Country	US
Kind code	B2
Filing date	Aug 4, 2017
Priority date	Aug 4, 2016
Publication date	Dec 17, 2019
Grant date	Dec 17, 2019

Abstract

An ignition control system is applied to an internal combustion engine having an ignition coil, a switching element and a measurement detection part which detects at least one of a primary and a secondary voltages and a secondary current. The ignition coil has a primary coil and a secondary coil. The switching element performs conduction and interruption the primary current to the primary coil. The ignition control system has a primary current control unit generating a spark discharge at the ignition plug by passing the primary current through the primary coil, and perform interruption of the primary current, and a discharge short-circuiting determination part determining a generation of discharge short-circuiting based on a measured value. The primary current control unit generates the spark discharge again when discharge short-circuiting occurs.

First claim

What is claimed is:

1. An ignition control system applied to an internal combustion engine, the internal combustion engine including:
an ignition plug which generates a spark discharge between a pair of discharge electrodes, the spark discharge ignites a combustible gas mixture in a cylinder of the internal combustion engine;
an ignition coil including a primary coil and a secondary coil, the ignition coil applies a secondary voltage to the ignition plug using the secondary coil;
a switching element which performs conduction and interruption of a primary current passing through the primary coil; and
a measurement detection part which detects a measured value of a primary voltage applied to the primary coil, a secondary current passing through the ignition plug and/or a secondary voltage applied to the ignition plug,
the ignition control system comprising:
a primary current control part that executes a discharge generation control for generating the spark discharge to the spark plug once or a plurality of times during one combustion cycle by causing the interruption of the primary current to the switching device after performing the energization of the primary current to the primary coil; and
a discharge short-circuiting determination part determining whether discharge short-circuiting has occurred or not based on the measured value detected from the measurement detection part, wherein,

when the discharge short-circuiting determination part determines that the discharge short-circuiting has occurred, the primary current control part causes the discharge generation control to be executed again by causing the switching element to conduct the primary current to the primary coil, and thereafter interrupts the primary current, and
the discharge short-circuiting determination part determines that the discharge short-circuiting has occurred during the one combustion cycle on the condition that a first instantaneous fluctuation larger than a predetermined value is detected in the measured value detected by the measurement detection part after conducting and interrupting the primary current to the primary coil by the switching element to generate the spark discharge.

2. The ignition control system as set forth in claim 1 , wherein,
the discharge short-circuiting determination part performs conduction and interruption of the primary current to the primary coil using the switching element during the one combustion cycle;
the discharge short-circuiting determination part does not detect the first instantaneous fluctuation whose measured value detected using the measurement detection part is larger than the predetermined value until a predetermined mask time is elapsed from when the spark discharge is generated; and
the discharge short-circuiting determination part detects the first instantaneous fluctuation whose measured value detected using the measurement detection part is larger than the predetermined value after the predetermined mask time is elapsed from when the spark discharge is generated.

3. The ignition control system as set forth in claim 2 , wherein,
the mask time may be set based on a driving state of the internal combustion engine.

4. The ignition control system as set forth in claim 2 , wherein,
the discharge short-circuiting determination part detects the first instantaneous fluctuation of the measured value detected using the measurement detection part only during a period from the predetermined mask time has elapsed to a predetermined determination time has elapsed.

5. The ignition control system as set forth in claim 1 , wherein,
the primary current control part makes the switching element pass the primary current through the primary coil when the discharge short-circuiting determination part determines that discharge short-circuiting has occurred; and
the primary current control part makes the switching element block the primary current to the primary coil when the primary current reaches a determination value.

6. The ignition control system as set forth in claim 1 , wherein,
the discharge generation control is executed again by making the primary current control part to make the switching element to block the primary current flowing to the primary coil after making the switching element to pass the primary current through the primary coil on condition that the discharge short-circuiting determination part determines that discharge short-circuiting has occurred.

7. The ignition control system as set forth in claim 1 , wherein,
the measurement detection part detects the secondary current passing through the ignition plug as the measured value; and
the discharge short-circuiting determination part determines that discharge short-circuiting has occurred on conditions that a minimum value of an absolute value of the secondary current of the measured value detected using the measurement detection part is larger than a first threshold and an instantaneous fluctuation whose maximum value of a differential value of the measured value is larger than a second threshold is detected.

8. The ignition control system as set forth in claim 1 , wherein,
the measurement detection part detects the secondary current passing through the ignition plug as the measured value; and
the discharge short-circuiting determination part determines that discharge short-circuiting has occurred on condition that an instantaneous fluctuation whose minimum value of the differential value of the measured value is smaller than a threshold and is larger than another threshold has been detected by the measurement detection part.

9. An ignition control system applied to an internal combustion engine, the internal combustion engine including:
a plurality of ignition plugs each of which has a pair of discharge electrodes between which a spark discharge is generated, the spark discharge ignites a combustible gas mixture in a plurality of cylinders of the internal combustion engine;
an ignition coil including a primary coil and a secondary coil, the ignition coil applies a secondary voltage to the ignition plug using the secondary coil;
a switching element which performs conduction and interruption of a primary current passing through the primary coil; and
a measurement detection part which detects a measured value of a primary voltage applied to the primary coil, a secondary current passing through the ignition plug and/or a secondary voltage applied to the ignition plug,
the ignition control system comprising:
a primary current control part that executes a discharge generation control for generating the spark discharge to the spark plug once or a plurality of times during one combustion cycle by causing the interruption of the primary current to the switching device after performing the energization of the primary current to the primary coil; and
a discharge short-circuiting determination part determining whether discharge short-circuiting has occurred or not based on the measured value detected from the measurement detection part, wherein

when the discharge short-circuiting determination part determines that the discharge short-circuiting has occurred, the primary current control part causes the discharge generation control to be executed again by causing the switching element to conduct the primary current to the primary coil, and thereafter interrupts the primary current, and
the discharge short-circuiting determination part determines that the discharge short-circuiting has occurred during the one combustion cycle on the condition that a first instantaneous fluctuation larger than a predetermined value is detected in the measured value detected by the measurement detection part after conducting and interrupting the primary current to t

Assignees

• Denso Corp

Inventors

• Doi Kaori
• Sugiura Akimitsu
• Aoki Fumiaki
• Nishio Noriaki
• Murayama Yuki

Classifications

• G01R19/165

  Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values · 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

• F02P3/0442

  using digital techniques (F02P3/0456, F02P3/053, F02P3/0554, F02P3/0558 take precedence) · CPC title

• F02P15/08

  having multiple-spark ignition, i.e. ignition occurring simultaneously at different places in one engine cylinder or in two or more separate engine cylinders · CPC title

• F02P2017/121

  by measuring spark voltage · CPC title