Leakage detecting device for an airtight vessel
First Claim
Patent Images
1. A leakage detecting device for an evaporated fuel gas system of an internal combustion engine, comprising:
- a) fuel tank (1),b) an evaporated fuel gas adsorbing canister (2) in open communication with an air/vapor space above fuel in the tank,c) first control valve means (9,
10) for communicating one end of the canister with the atmosphere,d) second control valve means (7,
8) for communicating another, opposite end of the canister with a negative pressure air intake (5) of the engine,e) an oxygen sensor (21) in open communication with said fuel tank space, andf) an electronic control unit (15) means for;
1) closing the first valve means,2) temporarily opening the second valve means to draw a partial vacuum in the fuel tank space and the canister, and thereafter closing the second valve means,3) determining when an increase in the oxygen level in the fuel tank space and the canister over a predetermined time span, as detected by the oxygen sensor, exceeds a predetermined normal value, and in response thereto4) producing an alarm.
1 Assignment
0 Petitions
Accused Products
Abstract
A leakage detecting device for an evaporated fuel gas system of an automobile draws and maintains a partial vacuum in the air space above the fuel in a tank 1 by temporarily connecting the space to the negatively pressurized intake manifold 5. An oxygen sensor 21 thereafter monitors the oxygen level in the evacuated space for a predetermined period of time, and if the oxygen increase exceeds a predetermined normal increase, a leakage alarm is given.
23 Citations
2 Claims
-
1. A leakage detecting device for an evaporated fuel gas system of an internal combustion engine, comprising:
-
a) fuel tank (1), b) an evaporated fuel gas adsorbing canister (2) in open communication with an air/vapor space above fuel in the tank, c) first control valve means (9,
10) for communicating one end of the canister with the atmosphere,d) second control valve means (7,
8) for communicating another, opposite end of the canister with a negative pressure air intake (5) of the engine,e) an oxygen sensor (21) in open communication with said fuel tank space, and f) an electronic control unit (15) means for; 1) closing the first valve means, 2) temporarily opening the second valve means to draw a partial vacuum in the fuel tank space and the canister, and thereafter closing the second valve means, 3) determining when an increase in the oxygen level in the fuel tank space and the canister over a predetermined time span, as detected by the oxygen sensor, exceeds a predetermined normal value, and in response thereto 4) producing an alarm. - View Dependent Claims (2)
-
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 AssigneeMitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
-
Original AssigneeMitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
-
InventorsYamashita, Akira, Yasui, Katsuaki
-
Primary Examiner(s)Williams, Hezron E.
-
Assistant Examiner(s)ROSKOS, JOSEPH
-
Application NumberUS08/067,116Time in Patent Office412 DaysField of Search73/49.2, 73/49.7, 73/118.1US Class Current73/49.2CPC Class CodesF02M 25/0809 Judging failure of purge co...F02M 25/0818 having means for pressurisi...F02M 25/089 Layout of the fuel vapour i...
