US 2003/0226549 A1 · Evaporative fuel processing apparatus and control method of same

Abstract

In an evaporative fuel processing apparatus, a fuel tank and a canister communicate with each other through a vapor passage, and an intake passage of an internal combustion engine and the canister communicates with each other through a purge passage. The evaporative fuel processing apparatus includes an open/close valve which opens or closes the vapor passage, a switching valve which makes the canister open to the atmosphere or isolates the canister from the atmosphere, a booster pump capable of applying pressure to the canister while the switching valve isolates the canister from the atmosphere, a purge control valve which opens or closes the purge passage, and an ECU which controls the open/close valve, the switching valve, the booster pump and the purge control valve.

Claims20

Dependent claims

An evaporative fuel processing apparatus comprising:

a fuel tank;
a canister which communicates with the fuel tank through a vapor passage;
a purge passage which allows an intake passage of an internal combustion engine and the canister to communicate with each other;
an open/close valve which opens or closes the vapor passage;
an isolated state switching mechanism which makes the canister open to an atmosphere or isolates the canister from the atmosphere;
a pressure adjusting mechanism which increases or decreases a pressure in the canister;
a purge control valve which opens or closes the purge passage;
and
a control system which controls the open/close valve, the isolated state switching mechanism, the pressure adjusting mechanism and the purge control valve.

6 more elements

A control method of an evaporative fuel processing apparatus comprising a fuel tank, a canister which communicates with the fuel tank through a vapor passage, a purge passage which allows an intake passage of an internal combustion engine and the canister to communicate with each other, an isolated state switching mechanism which makes the canister open to an atmosphere or which isolates the canister from the atmosphere, and a purge control valve which opens or closes the purge passage, comprising the steps of:

closing the canister space which includes the canister and which does not include the fuel tank by closing an open/close valve provided in the vapor passage, isolating the canister from the atmosphere using the isolated state switching mechanism, and closing the purge control valve;
adjusting an internal pressure in the closed canister space to increase or decrease;
and
performing a leakage diagnosis based on the internal pressure in the canister space adjusted by the canister space internal pressure adjusting mechanism.

1 more element

Dependencies are inferred from the claim text.

Evaporative fuel processing apparatus and control method of same

Life of this patent

Evaporative fuel processing apparatus and control method of same

Life of this patent

Abstract

Claims20