Fuel tank vapor control system with means for warning of malfunction of canister
First Claim
1. A fuel tank vapor control system for an automotive vehicle comprising:
- a fuel tank with hydrocarbon vapors;
a canister for adsorbing the hydrocarbon vapors from said fuel tank;
engine induction passage means;
purge passage means for supplying the hydrocarbon vapors regenerating from said canister to said engine induction passage means;
valve means for selectively opening and closing said purge passage means;
temperature sensor means for detecting an inside temperature of said canister;
judgement suspending means for suspending a judgement on malfunction of said canister when opening of said purge passage means is ineffective for causing an inside temperature fall of said canister, and once closing said purge passage means so that said canister fully adsorbs the hydrocarbon vapors; and
malfunction judging means for judging that said canister is malfunctioning when opening of said purge passage means after said closing thereof by said malfunction suspending means is still ineffective for causing an inside temperature fall of said canister.
1 Assignment
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Accused Products
Abstract
A fuel tank vapor control system is provided with an improved device for warning of malfunction of a canister. The device judges on malfunction of the canister on the basis of whether opening of a purge passage is effective for causing an inside temperature fall of the canister. In order to prevent an erroneous judgement on malfunction of the canister on the basis of an overflow condition of the canister, a purge passage is first closed so that the canister fully adsorbs hydrocarbon vapors from a fuel tank and then opened so that an inside temperature fall of the canister occurs. Opening and closing of the purge passage is repeated for several times so that a reliable judgement on malfunction of the canister is formed after lapse of a certain time and under a different operating condition of the canister.
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Citations
8 Claims
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1. A fuel tank vapor control system for an automotive vehicle comprising:
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a fuel tank with hydrocarbon vapors; a canister for adsorbing the hydrocarbon vapors from said fuel tank; engine induction passage means; purge passage means for supplying the hydrocarbon vapors regenerating from said canister to said engine induction passage means; valve means for selectively opening and closing said purge passage means; temperature sensor means for detecting an inside temperature of said canister; judgement suspending means for suspending a judgement on malfunction of said canister when opening of said purge passage means is ineffective for causing an inside temperature fall of said canister, and once closing said purge passage means so that said canister fully adsorbs the hydrocarbon vapors; and malfunction judging means for judging that said canister is malfunctioning when opening of said purge passage means after said closing thereof by said malfunction suspending means is still ineffective for causing an inside temperature fall of said canister. - View Dependent Claims (2)
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3. A fuel tank vapor control system for an automotive vehicle, comprising:
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a fuel tank with hydrocarbon vapors; a canister for adsorbing the hydrocarbon vapors from said fuel tank; engine induction passage means; purge passage means for supplying the hydrocarbon vapors regenerating from said canister to said engine induction passage means; valve means for selectively opening and closing said purge passage means; temperature sensor means for detecting an inside temperature of said canister and producing a signal representative thereof; and control means for controlling opening and closing of said purge passage means in response to the signal from said temperature sensor means, said control means having judgement suspending means for suspending a judgement on malfunction of said canister when opening of said purge passage means is ineffective for causing an inside temperature fall of said canister, and once closing said purge passage means so that said canister fully adsorbs the hydrocarbon vapors, and malfunction judging means for judging that said canister is malfunctioning when opening of said purge passage means after said closing thereof by said malfunction suspending means is still ineffective for causing an inside temperature fall of said canister. - View Dependent Claims (4, 5, 6, 7, 8)
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Specification