Evaporated fuel treatment device for internal combustion engine
First Claim
1. An evaporated fuel treatment device for internal combustion engine that uses a canister to absorb evaporated fuel generated in a fuel tank for evaporated fuel treatment purposes, said device comprising:
- a sealing valve for controlling the continuity between said fuel tank and said canister;
a purge control valve for controlling the continuity of a purge path for communication between said canister and the internal combustion engine;
a differential pressure generation means for producing a pressure differential between the inside and the outside of the canister;
a leak check means for activating said differential pressure generation means while said purge control valve is closed, and conducting a system leak check in accordance with a resulting pressure generated within a hermetically closed space containing said canister or within a hermetically closed space containing said fuel tank; and
a sealing valve diagnostic means for conducting a failure diagnostic check on said sealing valve simultaneously with the execution of processing for said leak check;
wherein said sealing valve diagnostic means comprises an open failure diagnostic means for activating said differential pressure generation means while said purge control valve and said sealing valve are closed, and conducting an open failure diagnostic check on said sealing valve in accordance with a resulting pressure generated within a hermetically closed space containing said canister or within a hermetically closed space containing said fuel tank; and
a close failure diagnostic means for conducting a close failure diagnostic check on said sealing valve in accordance with a differential pressure that is generated between both sides of said sealing valve upon said open failure diagnostic check.
1 Assignment
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Accused Products
Abstract
A sealing valve is installed between a fuel tank and a canister. A purge VSV is installed between the canister and an intake path. A pump module unit is installed to introduce a negative pressure into the canister. The negative pressure is introduced into the canister while the purge VSV and sealing valve are closed. An open failure diagnostic check is conducted on the sealing valve in accordance with the prevalent canister side pressure. A close failure diagnostic check is conducted on the sealing valve by making use of a differential pressure that is generated across the sealing valve as a result of the open failure diagnostic check.
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Citations
5 Claims
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1. An evaporated fuel treatment device for internal combustion engine that uses a canister to absorb evaporated fuel generated in a fuel tank for evaporated fuel treatment purposes, said device comprising:
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a sealing valve for controlling the continuity between said fuel tank and said canister;
a purge control valve for controlling the continuity of a purge path for communication between said canister and the internal combustion engine;
a differential pressure generation means for producing a pressure differential between the inside and the outside of the canister;
a leak check means for activating said differential pressure generation means while said purge control valve is closed, and conducting a system leak check in accordance with a resulting pressure generated within a hermetically closed space containing said canister or within a hermetically closed space containing said fuel tank; and
a sealing valve diagnostic means for conducting a failure diagnostic check on said sealing valve simultaneously with the execution of processing for said leak check;
wherein said sealing valve diagnostic means comprises an open failure diagnostic means for activating said differential pressure generation means while said purge control valve and said sealing valve are closed, and conducting an open failure diagnostic check on said sealing valve in accordance with a resulting pressure generated within a hermetically closed space containing said canister or within a hermetically closed space containing said fuel tank; and
a close failure diagnostic means for conducting a close failure diagnostic check on said sealing valve in accordance with a differential pressure that is generated between both sides of said sealing valve upon said open failure diagnostic check. - View Dependent Claims (2, 3, 4, 5)
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Specification