Evaporated fuel treatment apparatus
AssigneeAisan Kogyo Kabushiki Kaisha
InventorDaisaku Asanuma
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Abstract
An evaporated fuel treatment apparatus includes an abnormality determination unit that determines an abnormality of a purge passage. The abnormality determination unit changes an operating cycle of a purge control valve to a cycle longer than an initial set value while maintaining a duty ratio of the purge control valve set according to an operating state of an internal combustion engine, and determines an abnormality of the purge passage based on a first variation range and a second variation range calculated from a detection value detected by an airflow meter before and after the change of the operating cycle.
Claims10
An evaporated fuel treatment apparatus comprising:
- an airflow meter provided in an intake passage connected to an internal combustion engine;
- a vapor passage connected to a fuel tank;
- a canister that stores evaporated fuel to be fed from the fuel tank to the vapor passage;
- a purge passage connected to the intake passage and the canister;
- a purge pump provided in the purge passage;
- and
- a purge control valve provided in a downstream side of the purge pump,
- wherein the evaporated fuel treatment apparatus includes an abnormality determination unit configured to determine an abnormality of the purge passage, and
- the abnormality determination unit is configured to change an operating cycle of the purge control valve to a longer cycle than an initial set value while maintaining a duty ratio of the purge control valve set according to an operating state of the internal combustion engine, and determine whether the abnormality exists in the purge passage based on a first variation range and a second variation range which are calculated from detection values detected by the airflow meter before and after the operating cycle is changed.
An evaporated fuel treatment apparatus comprising:
- an airflow meter provided in an intake passage connected to an internal combustion engine;
- a vapor passage connected to a fuel tank;
- a canister that stores evaporated fuel to be fed from the fuel tank to the vapor passage;
- a purge passage connected to the intake passage and the canister;
- a purge pump provided in the purge passage;
- and
- a purge control valve provided in a downstream side of the purge pump,
- wherein the evaporated fuel treatment apparatus includes an abnormality determination unit configured to determine an abnormality of the purge passage, and
- the abnormality determination unit is configured to determine whether the abnormality exists in the purge passage based on a difference between a variation cycle of a detection value detected by the airflow meter and an operating cycle of the purge control valve while maintaining a duty ratio of the purge control valve set according to an operating state of the internal combustion engine.
Dependencies are inferred from the claim text.