Ignition apparatus for internal combustion engine
AssigneeDenso Corporation
InventorMasashi Irie
Life of this patent
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Abstract
In an ignition apparatus, a deterioration determination circuit performs a deterioration determination task of (i) monitoring an absolute increase in a temperature parameter during a predetermined deterioration detection period that has been started since an energization command signal being inputted to a control circuit, and (ii) performing a comparison between the absolute increase in the temperature parameter and a predetermined deterioration detection threshold to thereby determine whether a level of deterioration of a switching circuit is within an acceptable level.
Claims8
An ignition apparatus for controlling energization of a primary winding of an ignition coil to accordingly generate an ignition voltage across a secondary winding of the ignition coil, the ignition apparatus comprising:
- a switching circuit comprising a switch connected to the primary winding;
- and
- a control circuit comprising:
- a driver configured to control energization of the switch in response to an energization command signal inputted thereto;
- an overtemperature protection circuit configured to:
- monitor a temperature parameter representing a temperature of the switch;
- cause the driver to energize the switch upon determination that the temperature of the switch obtained based on the monitored temperature parameter is lower than or equal to a predetermined prevention temperature;
- and
- cause the driver to shut down the energization of the switch upon determination that the temperature of the switch obtained based on the monitored temperature parameter is higher than the predetermined prevention temperature;
- and
- a deterioration determination circuit configured to perform a deterioration determination task of:
- monitoring an absolute value of a change in the temperature parameter during a predetermined deterioration detection period that has been started since the energization command signal being inputted to the control circuit;
- and
- performing a comparison between the absolute value of the change in the temperature parameter and a predetermined deterioration detection threshold to thereby determine whether a level of deterioration of the switching circuit is within an acceptable level.
Dependencies are inferred from the claim text.