Device and method for diagnosing evaporated fuel processing device
First Claim
1. A diagnostic apparatus for an evaporated fuel processing apparatus, wherein the evaporated fuel processing apparatus includes a blocking valve configured to selectively allow and shut off communication between a canister and a fuel tank, and adsorbs evaporated fuel by the canister during fuel filling, wherein the evaporated fuel occurs in the fuel tank, and introduces into an intake air line of an internal combustion engine and processes the evaporated fuel while the internal combustion engine is operating, the diagnostic apparatus comprising:
- a pump configured to pressurize an inside of a system, wherein the system includes the fuel tank and the canister; and
at least one pressure sensor configured to sense an internal pressure of the system;
wherein the diagnostic apparatus is configured to;
diagnose whether or not leakage is present, based on a change in the internal pressure of the system from a pressurized state, wherein the pressurized state is a state pressurized to a predetermined pressure for diagnosis that is higher than a tank pressure at start of diagnosis; and
maintain an inside of the fuel tank in the pressurized state by closing the blocking valve after termination of the diagnosis.
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Accused Products
Abstract
An evaporated fuel processing apparatus includes a valve between a canister and a fuel tank, and adsorbs evaporated fuel by the canister during fuel filling, and introduces into an intake air line of an internal combustion engine and processes the evaporated fuel while the internal combustion engine is operating. A diagnostic apparatus includes: a pump for pressurizing a system including the fuel tank and the canister; and a pressure sensor for sensing an internal pressure of the system. The diagnostic apparatus diagnoses whether or not leakage is present, based on a change in the internal pressure of the system from a pressurized state, wherein the pressurized state is a state pressurized to a predetermined pressure for diagnosis that is higher than a tank pressure at start of diagnosis; and maintains the fuel tank in the pressurized state by closing the valve after termination of the diagnosis.
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Citations
10 Claims
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1. A diagnostic apparatus for an evaporated fuel processing apparatus, wherein the evaporated fuel processing apparatus includes a blocking valve configured to selectively allow and shut off communication between a canister and a fuel tank, and adsorbs evaporated fuel by the canister during fuel filling, wherein the evaporated fuel occurs in the fuel tank, and introduces into an intake air line of an internal combustion engine and processes the evaporated fuel while the internal combustion engine is operating, the diagnostic apparatus comprising:
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a pump configured to pressurize an inside of a system, wherein the system includes the fuel tank and the canister; and at least one pressure sensor configured to sense an internal pressure of the system; wherein the diagnostic apparatus is configured to; diagnose whether or not leakage is present, based on a change in the internal pressure of the system from a pressurized state, wherein the pressurized state is a state pressurized to a predetermined pressure for diagnosis that is higher than a tank pressure at start of diagnosis; and maintain an inside of the fuel tank in the pressurized state by closing the blocking valve after termination of the diagnosis. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A diagnostic method for an evaporated fuel processing apparatus, wherein the evaporated fuel processing apparatus includes a blocking valve configured to selectively allow and shut off communication between a canister and a fuel tank, and adsorbs evaporated fuel by the canister during fuel filling, wherein the evaporated fuel occurs in the fuel tank, and introduces into an intake air line of an internal combustion engine and processes the evaporated fuel while the internal combustion engine is operating, the diagnostic method comprising:
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bringing an inside of a system into hermetic state, wherein the system includes the fuel tank and the canister; pressurizing the inside of the system into a pressurized state by a pump, wherein the pressurized state is a state pressurized to a predetermined pressure for diagnosis that is higher than a tank pressure at start of diagnosis; diagnosing whether or not leakage is present, based on a change in an internal pressure of the system after termination of the pressurization; and maintaining an inside of the fuel tank in the pressurized state by maintaining the blocking valve in closed state after termination of the diagnosis. - View Dependent Claims (8, 9)
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10. A diagnostic apparatus for an evaporated fuel processing apparatus, wherein the evaporated fuel processing apparatus includes a blocking valve configured to selectively allow and shut off communication between a canister and a fuel tank, and adsorbs evaporated fuel by the canister during fuel filling, wherein the evaporated fuel occurs in the fuel tank, and introduces into an intake air line of an internal combustion engine and processes the evaporated fuel while the internal combustion engine is operating, the diagnostic apparatus comprising:
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a pump configured to pressurize an inside of a system via a canister side of the system closer to the canister with respect to the blocking valve, wherein the system includes the fuel tank and the canister; and a canister side pressure sensor configured to sense a pressure of the canister side of the system with respect to the blocking valve; a fuel tank side pressure sensor configured to sense a pressure of a fuel tank side of the system closer to the fuel tank with respect to the blocking valve; wherein the diagnostic apparatus is configured to; start the pressurization by the pump with the blocking valve closed; bring the entire system into a pressurized state by opening the blocking valve, in response to a condition that the pressure of the canister side with respect to the blocking valve becomes higher than the pressure of the fuel tank side with respect to the blocking valve; diagnose whether or not leakage is present, based on a change in an internal pressure of the system from the pressurized state; and maintain an inside of the fuel tank in the pressurized state via the blocking valve after termination of the diagnosis.
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Specification