Diagnosis apparatus for fuel vapor purge system and method thereof
First Claim
Patent Images
1. A diagnosis apparatus for a fuel vapor purge system which traps the fuel vapor generated in a fuel tank to a canister, to purge the fuel vapor trapped to said canister to an intake passage of an internal combustion engine, comprising:
- a pressure generator forcibly changing a pressure in a shielded purge passage inclusive of said fuel tank;
a pressure detector detecting the pressure in said purge passage; and
a diagnosis device forcibly changing the pressure in said purge passage by said pressure generator and also receiving a detection signal from said pressure detector, to diagnose whether or not the leakage occurs in said purge passage,wherein said diagnosis device starts the diagnosis processing from a standby period that has elapsed after an operation of said internal combustion engine was stopped, andwherein said diagnosis device calculates a standby time defining the standby period when said internal combustion engine has been stopped, and starts said diagnosis processing from said standby time that has elapsed after the operation of said internal combustion engine was stopped.
3 Assignments
0 Petitions
Accused Products
Abstract
In a fuel vapor purge system, a diagnosis section inclusive of a fuel tank is pressurized from the generation of fuel vapor in the fuel tank has been finished after an operation of an engine was stopped, and the diagnosis is performed based on a pressure in the diagnosis section.
-
Citations
19 Claims
-
1. A diagnosis apparatus for a fuel vapor purge system which traps the fuel vapor generated in a fuel tank to a canister, to purge the fuel vapor trapped to said canister to an intake passage of an internal combustion engine, comprising:
-
a pressure generator forcibly changing a pressure in a shielded purge passage inclusive of said fuel tank; a pressure detector detecting the pressure in said purge passage; and a diagnosis device forcibly changing the pressure in said purge passage by said pressure generator and also receiving a detection signal from said pressure detector, to diagnose whether or not the leakage occurs in said purge passage, wherein said diagnosis device starts the diagnosis processing from a standby period that has elapsed after an operation of said internal combustion engine was stopped, and wherein said diagnosis device calculates a standby time defining the standby period when said internal combustion engine has been stopped, and starts said diagnosis processing from said standby time that has elapsed after the operation of said internal combustion engine was stopped. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. A diagnosis apparatus for a fuel vapor purge system which traps the fuel vapor generated in a fuel tank to a canister, to purge the fuel vapor trapped to said canister to an intake passage of an internal combustion engine, comprising:
-
a pressure generator forcibly changing a pressure in a shielded purge passage inclusive of said fuel tank; a pressure detector detecting the pressure in said purge passage; a diagnosis device forcibly changing the pressure in said purge passage by said pressure generator and also receiving a detection signal from said pressure detector, to diagnose whether or not the leakage occurs in said purge passage; and a diagnosis start condition detector detecting a diagnosis start condition, wherein said diagnosis device starts the diagnosis processing from a standby period that has elapsed after an operation of said internal combustion engine was stopped, wherein said diagnosis device sets a period until said diagnosis start condition is detected after the operation of said internal combustion engine has been stopped, as said standby period, and wherein said diagnosis start condition detector; includes an environmental temperature detector detecting an environmental temperature of fuel, and detects that said environmental temperature becomes lower than a threshold after the operation of said internal combustion engine has been stopped, as said diagnosis start condition.
-
-
9. A diagnosis apparatus for a fuel vapor purge system which traps the fuel vapor generated in a fuel tank to a canister, to purge the fuel vapor trapped to said canister to an intake passage of an internal combustion engine, comprising:
-
a pressure generator forcibly changing a pressure in a shielded purge passage inclusive of said fuel tank; a pressure detector detecting the pressure in said purge passage; a diagnosis device forcibly changing the pressure in said purge passage by said pressure generator and also receiving a detection signal from said pressure detector, to diagnose whether or not the leakage occurs in said purge passage; and a diagnosis start condition detector detecting a diagnosis start condition, wherein said diagnosis device starts the diagnosis processing from a standby period that has elapsed after an operation of said internal combustion engine was stopped, wherein said diagnosis device sets a period until said diagnosis start condition is detected after the operation of said internal combustion engine has been stopped, as said standby period, and wherein said diagnosis start condition detector; includes a fuel temperature detector detecting a fuel temperature in said fuel tank, and detects that said fuel temperature becomes lower than a threshold after the operation of said internal combustion engine has been stopped, as said diagnosis start condition.
-
-
10. A diagnosis apparatus for a fuel vapor purge system which traps the fuel vapor generated in a fuel tank to a canister, to purge the fuel vapor trapped to said canister to an intake passage of an internal combustion engine, comprising:
-
a pressure generator forcibly changing a pressure in a shielded purge passage inclusive of said fuel tank; a pressure detector detecting the pressure in said purge passage; a diagnosis device forcibly changing the pressure in said purge passage by said pressure generator and also receiving a detection signal from said pressure detector, to diagnose whether or not the leakage occurs in said purge passage; and a diagnosis start condition detector detecting a diagnosis start condition. wherein said diagnosis device starts the diagnosis processing from a standby period that has elapsed after an operation of said internal combustion engine was stopped, wherein said diagnosis device sets a period until said diagnosis start condition is detected after the operation of said internal combustion engine has been stopped, as said standby period, and wherein said diagnosis start condition detector detects that the pressure detected by said pressure detector becomes lower than a threshold after the operation of said internal combustion engine has been stopped, as said diagnosis start condition.
-
-
11. A diagnosis method for a fuel vapor purge system which traps the fuel vapor generated in a fuel tank to a canister, to purge the fuel vapor trapped to said canister to an intake passage of an internal combustion engine, comprising the steps of:
-
judging whether or not a standby period has elapsed after an operation of said internal combustion engine was stopped; forcibly changing a pressure in a shielded purge passage inclusive of said fuel tank after said standby period has elapsed; detecting the pressure in said purge passage; diagnosing whether or not the leakage occurs in said purge passage, based on the detected pressure; and calculating a standby time defining said standby period, by; detecting a fuel temperature in said fuel tank, and calculating said standby time based on the detected fuel temperature.
-
-
12. A diagnosis method for a fuel vapor purge system which traps the fuel vapor generated in a fuel tank to a canister, to purge the fuel vapor trapped to said canister to an intake passage of an internal combustion engine, comprising the steps of:
-
judging whether or not a standby period has elapsed after an operation of said internal combustion engine was stopped; forcibly changing a pressure in a shielded purge passage inclusive of said fuel tank after said standby period has elapsed; detecting the pressure in said purge passage; diagnosing whether or not the leakage occurs in said purge passage, based on the detected pressure; and calculating a standby time defining said standby period, by; estimating a fuel temperature in said fuel tank; and calculating said standby time based on the estimated fuel temperature.
-
-
13. A diagnosis method for a fuel vapor purge system which traps the fuel vapor generated in a fuel tank to a canister, to purge the fuel vapor trapped to said canister to an intake passage of an internal combustion engine, comprising the steps of:
-
judging whether or not a standby period has elapsed after an operation of said internal combustion engine was stopped; forcibly changing a pressure in a shielded purge passage inclusive of said fuel tank after said standby period has elapsed; detecting the pressure in said purge passage; diagnosing whether or not the leakage occurs in said purge passage, based on the detected pressure; and calculating a standby time defining said standby period, by; detecting a fuel property in said fuel tank; and calculating said standby time based on the detected fuel property.
-
-
14. A diagnosis method for a fuel vapor purge system which traps the fuel vapor generated in a fuel tank to a canister, to purge the fuel vapor trapped to said canister to an intake passage of an internal combustion engine, comprising the steps of:
-
judging whether or not a standby period has elapsed after an operation of said internal combustion engine was stopped; forcibly changing a pressure in a shielded purge passage inclusive of said fuel tank after said standby period has elapsed; detecting the pressure in said purge passage; diagnosing whether or not the leakage occurs in said purge passage, based on the detected pressure; and calculating a standby time defining said standby period, by; detecting a fuel level in said fuel tank; and calculating said standby time based on the detected fuel level.
-
-
15. A diagnosis method for a fuel vapor purge system which traps the fuel vapor generated in a fuel tank to a canister, to purge the fuel vapor trapped to said canister to an intake passage of an internal combustion engine, comprising the steps of:
-
judging whether or not a standby period has elapsed after an operation of said internal combustion engine was stopped; forcibly changing a pressure in a shielded purge passage inclusive of said fuel tank after said standby period has elapsed; detecting the pressure in said purge passage; diagnosing whether or not the leakage occurs in said purge passage, based on the detected pressure; and calculating a standby time defining said standby period, by; detecting environmental conditions of said internal combustion engine; and calculating said standby time based on the detected environmental conditions.
-
-
16. A diagnosis method for a fuel vapor purge system which traps the fuel vapor generated in a fuel tank to a canister, to purge the fuel vapor trapped to said canister to an intake passage of an internal combustion engine, comprising the steps of:
-
judging whether or not a standby period has elapsed after an operation of said internal combustion engine was stopped; forcibly changing a pressure in a shielded purge passage inclusive of said fuel tank after said standby period has elapsed; detecting the pressure in said purge passage; diagnosing whether or not the leakage occurs in said purge passage, based on the detected pressure; and calculating a standby time defining said standby period, by; detecting the pressure in said purge passage; and calculating said standby time based on the detected pressure.
-
-
17. A diagnosis method for a fuel vapor purge system which traps the fuel vapor generated in a fuel tank to a canister, to purge the fuel vapor trapped to said canister to an intake passage of an internal combustion engine, comprising the steps of:
-
judging whether or not a standby period has elapsed after an operation of said internal combustion engine was stopped; forcibly changing a pressure in a shielded purge passage inclusive of said fuel tank after said standby period has elapsed; detecting the pressure in said purge passage; and diagnosing whether or not the leakage occurs in said purge passage, based on the detected pressure, wherein said step of judging whether or not the standby period has elapsed comprises the steps of; detecting a diagnosis start condition; and judging that said standby period has elapsed, at the time when said diagnosis start condition is detected after the operation of said internal combustion engine has been stopped, and wherein said step of detecting the diagnosis start condition comprises the steps of; detecting an environmental temperature of fuel; and judging whether or not said environmental temperature becomes lower than a threshold after the operation of said internal combustion engine has been stopped.
-
-
18. A diagnosis method for a fuel vapor purge system which traps the fuel vapor generated in a fuel tank to a canister, to purge the fuel vapor trapped to said canister to an intake passage of an internal combustion engine, comprising the steps of:
-
judging whether or not a standby period has elapsed after an operation of said internal combustion engine was stopped; forcibly changing a pressure in a shielded purge passage inclusive of said fuel tank after said standby period has elapsed; detecting the pressure in said purge passage; and diagnosing whether or not the leakage occurs in said purge passage, based on the detected pressure, wherein said step of judging whether or not the standby period has elapsed comprises the steps of; detecting a diagnosis start condition; and judging that said standby period has elapsed, at the time when said diagnosis start condition is detected after the operation of said internal combustion engine has been stopped, and wherein said step of detecting the diagnosis start condition comprises the steps of; detecting a fuel temperature in said fuel tank; and judging whether or not said fuel temperature becomes lower than a threshold after the operation of said internal combustion engine has been stopped.
-
-
19. A diagnosis method for a fuel vapor purge system which traps the fuel vapor generated in a fuel tank to a canister, to purge the fuel vapor trapped to said canister to an intake passage of an internal combustion engine, comprising the steps of:
-
judging whether or not a standby period has elapsed after an operation of said internal combustion engine was stopped; forcibly changing a pressure in a shielded purge passage inclusive of said fuel tank after said standby period has elapsed; detecting the pressure in said purge passage; and diagnosing whether or not the leakage occurs in said purge passage, based on the detected pressure, wherein said step of judging whether or not the standby period has elapsed comprises the steps of; detecting a diagnosis start condition; and judging that said standby period has elapsed, at the time when said diagnosis start condition is detected after the operation of said internal combustion engine has been stopped, and wherein said step of detecting the diagnosis start condition comprises the steps of; detecting the pressure in said purge passage; and judging whether or not said pressure becomes lower than a threshold after the operation of said internal combustion engine has been stopped.
-
Specification