Fuel supply apparatus for and pressure control method of internal combustion engine
First Claim
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1. A fuel supply apparatus for an internal combustion engine, comprising:
- a fuel tank;
a pump for changing a pressure that prevails in the fuel tank;
a sensor for detecting the pressure in the fuel tank;
a diagnostic device for detecting a leak in a fuel vapor treatment system including the fuel tank; and
a control device for controlling the pump by setting, when a leak has been detected by the diagnostic device, a target pressure in a steady state to a value lower than a case where the leak has not been detected, and by comparing the pressure detected by the sensor and the target pressure in the steady state.
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Abstract
A leak diagnosing technology in which a diagnostic space capable of being closed is defined which includes therein a fuel tank and a canister, the closed diagnostic space being pressurized by an air pump to diagnose of presence or absence of a leak in the diagnostic space based on whether or not a pressure in the diagnostic space indicates a predetermined pressure change. When the diagnosis is completed, the air pump is reversely rotated to cause a reduction in the pressure in the diagnostic space to thereby quickly return the pressure to a target pressure in a steady state.
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Citations
19 Claims
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1. A fuel supply apparatus for an internal combustion engine, comprising:
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a fuel tank; a pump for changing a pressure that prevails in the fuel tank; a sensor for detecting the pressure in the fuel tank; a diagnostic device for detecting a leak in a fuel vapor treatment system including the fuel tank; and a control device for controlling the pump by setting, when a leak has been detected by the diagnostic device, a target pressure in a steady state to a value lower than a case where the leak has not been detected, and by comparing the pressure detected by the sensor and the target pressure in the steady state. - View Dependent Claims (9)
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2. A fuel supply apparatus for an internal combustion engine, comprising:
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a fuel tank; an electric pump for changing a pressure that prevails in the fuel tank and capable of varying its rotating direction between a normal direction and a reverse direction in response to switching of a direction in which electric voltage is applied; a sensor for detecting the pressure in the fuel tank; and a control device for comparing the pressure detected by the sensor and a target pressure in a steady state, and controlling the pump based on the comparison result. - View Dependent Claims (3, 4)
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5. A fuel supply apparatus for an internal combustion engine, comprising:
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a fuel tank; a pump capable of varying a rotating direction thereof between a normal direction and a reverse direction to thereby switch an inside of the fuel tank between a pressurizing state and a depressurizing state; a sensor for detecting a pressure in the fuel tank; a diagnostic device configured to change the pressure in the fuel tank by the pump to thereby detect a leak in a fuel vapor treatment system including the fuel tank, and to diagnose whether the leak is present or absent based on the pressure prevailing in the fuel tank; and a control device for reversing the rotating direction of the pump after the diagnosis by the diagnostic device has been completed to thereby return the pressure in the fuel tank to the target pressure in the steady state. - View Dependent Claims (6, 7, 8)
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10. A fuel supply apparatus for an internal combustion engine, comprising:
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a fuel tank; an electric pump for changing a pressure prevailing in the fuel tank and capable of varying its rotating direction between a normal direction and a reverse direction in response to switching of a direction in which electric voltage is applied; pressure detecting means for detecting the pressure in the fuel tank; and controlling means for controlling the electric pump based on comparison between the pressure detected by the pressure detecting means and a target pressure in a steady state.
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11. A method of controlling a pressure prevailing in a fuel supply apparatus of an internal combustion engine, the fuel supply apparatus including a fuel tank and a pump capable of changing the pressure prevailing in the fuel tank, wherein the method comprises the steps of:
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detecting the pressure in the fuel tank; setting a target value of the pressure in the fuel tank in a steady state; changing the pressure in the fuel tank by the pump to thereby detect a leak in a fuel vapor treatment system including the fuel tank, and diagnosing whether the leak is present or absent based on the pressure prevailing in the fuel tank; varying, when the leak has been detected, the target pressure in the steady state to a pressure value lower than in a case where the leak has not been; and controlling the pump based on a detected value of the pressure and the target value. - View Dependent Claims (19)
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12. A method of controlling a pressure prevailing in a fuel supply apparatus of an internal combustion engine, the fuel supply apparatus including a fuel tank and a pump capable of changing the pressure prevailing in the fuel tank, wherein the method comprises the steps of:
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detecting the pressure in the fuel tank; setting a target value of the pressure in the fuel tank in a steady state; calculating a deviation of the detected value of the pressure and the target value from each other; and switching a rotating direction of the pump between a normal direction and a reverse direction according to the deviation. - View Dependent Claims (14, 15)
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13. A method of controlling a pressure prevailing in a fuel supply apparatus of an internal combustion engine, the fuel supply apparatus including a fuel tank and a pump capable of changing the pressure prevailing in the fuel tank, wherein the method comprises the steps of:
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changing the pressure in the fuel tank by the pump to thereby detect a leak in a fuel vapor treatment system including the fuel tank; detecting the pressure in the fuel tank; setting a target value of the pressure in the fuel tank in a steady state; determining the end of the leak detection; and controlling the pump based on the detected value of the pressure and the target value after completion of detection of the leak. - View Dependent Claims (16, 17, 18)
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Specification