IGNITION DEVICE
First Claim
1. An ignition device comprising:
- a spark plug that generates a plasma discharge between a pair of discharge electrodes for igniting a combustible mixture in a combustion chamber of an internal combustion engine;
an ignition coil having a primary coil and a secondary coil that applies a voltage between the pair of discharge electrodes of the spark plug by the secondary coil;
a measurement value detecting section that detects at least one measurement value among a primary current flowing through the primary coil, a primary voltage applied to the primary coil, a secondary current flowing through the ignition plug, and a secondary voltage applied to the spark plug;
an electrical breakdown determiner that determines whether or not a discharge between the pair of discharge electrodes has become an electrical breakdown state based on the measurement value detected by the measurement value detecting section;
an AC voltage applying section that applies an AC voltage of a first predetermined frequency, which causes voltage resonance in a circuit including the spark plug and the secondary coil, in the primary coil; and
a first changing section that changes the frequency of the AC voltage outputted by the AC voltage applying section to a second predetermined frequency that can maintain the electrical breakdown state, and is lower in frequency than the first predetermined frequency when it is determined by the electrical breakdown determiner that the discharge has become the electrical breakdown state.
1 Assignment
0 Petitions
Accused Products
Abstract
An ignition device includes a spark plug, a measurement value detector, an electrical breakdown determiner, an AC voltage applying section, and a first changing section. The measurement value detector includes primary and secondary coils, and detects at least one measurement value among an ignition coil, a primary current, a primary voltage, a secondary current, and a secondary voltage. The electrical breakdown determiner determines whether a discharge has become an electrical breakdown state based on the measurement value. The AC voltage applying section applies an AC voltage of a first predetermined frequency that causes voltage resonance to the primary coil. The first changing section changes the frequency of the AC voltage to a second predetermined frequency that can maintain the electrical breakdown state and is lower in frequency than the first predetermined frequency when it is determined that the discharge has become the electrical breakdown state.
-
Citations
9 Claims
-
1. An ignition device comprising:
-
a spark plug that generates a plasma discharge between a pair of discharge electrodes for igniting a combustible mixture in a combustion chamber of an internal combustion engine; an ignition coil having a primary coil and a secondary coil that applies a voltage between the pair of discharge electrodes of the spark plug by the secondary coil; a measurement value detecting section that detects at least one measurement value among a primary current flowing through the primary coil, a primary voltage applied to the primary coil, a secondary current flowing through the ignition plug, and a secondary voltage applied to the spark plug; an electrical breakdown determiner that determines whether or not a discharge between the pair of discharge electrodes has become an electrical breakdown state based on the measurement value detected by the measurement value detecting section; an AC voltage applying section that applies an AC voltage of a first predetermined frequency, which causes voltage resonance in a circuit including the spark plug and the secondary coil, in the primary coil; and a first changing section that changes the frequency of the AC voltage outputted by the AC voltage applying section to a second predetermined frequency that can maintain the electrical breakdown state, and is lower in frequency than the first predetermined frequency when it is determined by the electrical breakdown determiner that the discharge has become the electrical breakdown state. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
Specification