Failure diagnostic apparatus for fuel vapor purge system and fuel vapor purge apparatus and combustion engine having failure diagnostic apparatus
First Claim
Patent Images
1. A failure diagnostic apparatus for a fuel vapor purge system adsorbing in a canister fuel vapor generated in a fuel tank and purging the adsorbed fuel vapor into an intake system, comprising:
- pressure difference generation means for generating, when failure diagnosis is executed, a pressure difference between respective pressures inside and outside a fuel vapor path including said fuel tank and said canister;
failure diagnostic means for comparing, with a predetermined reference pressure, the pressure inside said fuel vapor path when said pressure difference generation means generates said pressure difference, for conducting said failure diagnosis to determine whether failure occurs or not based on result of the comparison;
execution determination means for determining, based on whether or not an amount of fuel vapor in said fuel vapor path is smaller than a predetermined reference amount, whether or not said failure diagnosis is to be executed by said pressure difference generation means and said failure diagnostic means; and
said execution determination means determines, when an amount of fuel vapor adsorbed in said canister is smaller than a first predetermined amount, that said amount of fuel vapor in said fuel vapor path is smaller than said predetermined reference amount.
1 Assignment
0 Petitions
Accused Products
Abstract
When a purge amount while an engine is running is a first purge amount and the purge amount before failure diagnosis is larger than a required purge amount, an amount adsorbed in a canister before the failure diagnosis is executed is smaller than a predetermined determination value. Accordingly, an ECU executes the failure diagnosis. When the purge amount while the engine is running is a second purge amount and the purge amount before the failure diagnosis is equal to or smaller than the required purge amount, the amount adsorbed in the canister before the failure diagnosis is equal to or larger than the predetermined determination value. Accordingly the ECU does not execute the failure diagnosis. The required purge amount used for determining whether or not the failure diagnosis can be executed is determined according to the temperature before the failure diagnosis.
-
Citations
14 Claims
-
1. A failure diagnostic apparatus for a fuel vapor purge system adsorbing in a canister fuel vapor generated in a fuel tank and purging the adsorbed fuel vapor into an intake system, comprising:
-
pressure difference generation means for generating, when failure diagnosis is executed, a pressure difference between respective pressures inside and outside a fuel vapor path including said fuel tank and said canister; failure diagnostic means for comparing, with a predetermined reference pressure, the pressure inside said fuel vapor path when said pressure difference generation means generates said pressure difference, for conducting said failure diagnosis to determine whether failure occurs or not based on result of the comparison; execution determination means for determining, based on whether or not an amount of fuel vapor in said fuel vapor path is smaller than a predetermined reference amount, whether or not said failure diagnosis is to be executed by said pressure difference generation means and said failure diagnostic means; and said execution determination means determines, when an amount of fuel vapor adsorbed in said canister is smaller than a first predetermined amount, that said amount of fuel vapor in said fuel vapor path is smaller than said predetermined reference amount. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A failure diagnostic apparatus for a fuel vapor purge system adsorbing in a canister fuel vapor generated in a fuel tank and purging the adsorbed fuel vapor into an intake system, comprising:
-
pressure difference generation means for generating, when failure diagnosis is executed, a pressure difference between respective pressures inside and outside a fuel vapor path including said fuel tank and said canister; failure diagnostic means for comparing, with a predetermined reference pressure, the pressure inside said fuel vapor path when said pressure difference generation means generates said pressure difference, for conducting said failure diagnosis to determine whether failure occurs or not based on result of the comparison; concentration detection means for detecting a concentration of the fuel vapor in said fuel vapor path; and execution determination means for determining, based on whether or not said concentration of the fuel vapor detected by said concentration detection means is lower than a predetermined value, whether or not said failure diagnosis is to be executed by said pressure difference generation means and said failure diagnostic means. - View Dependent Claims (12, 13, 14)
-
Specification
-
- Resources
Litigation Campaign Assessment
Thank you for your request. You will receive a custom alert email when the Litigation Campaign Assessment is available.
×
-
Current AssigneeDENSO Corporation, Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
-
Original AssigneeDENSO Corporation, Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
-
InventorsIto, Tokiji, Nagasaki, Kenji, Miyahara, Hideki
-
Primary Examiner(s)MCCALL, ERIC SCOTT
-
Application NumberUS11/099,614Publication NumberTime in Patent Office657 DaysField of Search73/40, 73/46, 73/47, 73/497, 731/16, 731/172, 731/173, 731/181US Class Current73/114.39CPC Class CodesF02M 25/08 adding fuel vapours drawn f...F02M 25/0818 having means for pressurisi...F02M 25/089 Layout of the fuel vapour i...
