Patent ID: 8701473

Claim:
An end-of-life estimation device for an air cleaner, which is disposed in an intake passage of an internal combustion engine, for estimating an end of a service life of the air cleaner that filters intake air drawn into the engine through the intake passage, which is dependent on clogging of the air cleaner, comprising: life parameter-calculating means for calculating a life parameter indicative of a remaining service life of the air cleaner during running of the engine, on an as needed basis; intake air amount-detecting means for detecting an intake air amount; intake parameter-detecting means for detecting an intake parameter which is at least one of pressure of intake air on a downstream side of the air cleaner and an opening degree of a throttle valve for adjusting the intake air amount; storage means for storing a relationship between a degree of clogging of the air cleaner, the intake air amount, and the intake parameter; and reference value-updating means for calculating and updating a reference value of the life parameter with reference to which said life parameter-calculating means calculates the life parameter, based on the relationship stored in said storage means, according to the intake air amount and the detected intake parameter, when the detected intake air amount is not smaller than a predetermined value, and wherein the reference value-calculating means calculates and updates the reference value repeatedly such that the life parameter and the reference value are corrected close to a true service life line extending from a value of the life parameter representing a new air cleaner to a predetermined value representing the end of life of the air cleaner.