Back to results
US 8,074,627 B2Granted
Automotive fuel system leak testing
AssigneeFord Global Technologies, LLC
InventorShahid Ahmed Siddiqui
Life of this patent
Estimating the term…
Abstract
Systems and methods for performing leak testing on fuel system components in hybrid vehicles during engine-off operating conditions are disclosed. For example, a fuel tank may include a pressure accumulator which may be filled with fuel via a fuel pump in order to generate a vacuum which may be used to diagnose leaks in the fuel system.
Claims17
A method of operating an engine emission control system, comprising:
- during an engine-off condition, selectively operating a fuel pump to store at least some pressure in an accumulator coupled to the fuel pump, the accumulator positioned within a fuel tank, and including a flexible bladder within a rigid bottle and a drain line with a selectively-sealable aperture;
- and
- indicating a leak in the emission control system in response to the stored pressure.
A method of operating an engine emission control system in a hybrid vehicle including a fuel tank, comprising:
- during an engine-off condition, isolating the fuel tank from the atmosphere, and selectively operating a fuel pump to store at least some fuel in an accumulator coupled to the fuel pump and positioned within the fuel tank;
- and
- indicating a fuel tank leak in response to a pressure change after fuel is stored in the accumulator, wherein the accumulator includes a bladder within a rigid bottle and a drain line with an aperture, the drain line with an aperture including a sealing member configured to seal the aperture when the fuel pump is in operation and allow fuel in the accumulator to drain into the fuel tank when the fuel pump is not in operation.
A hybrid vehicle system, comprising:
- an engine emission control system including a fuel vapor retaining device coupled to a fuel tank through a valve;
- a fuel pump within the fuel tank coupled to a pressure accumulator device within the fuel tank;
- a pressure sensor disposed within the fuel tank;
- and
- a computer readable storage medium having instructions encoded thereon, including:
- instructions to, during an engine-off condition, selectively operate the fuel pump to store at least some pressure in the pressure accumulator device;
- instructions to indicate a leak in the emission control system in response to the stored pressure;
- and
- instructions to, during an engine running condition, operate the fuel pump to deliver fuel to the engine and initiate a spark in a cylinder of the engine to combust the delivered fuel, wherein the pressure accumulator device includes a bladder within a rigid bottle and a drain line with an aperture, the drain line with the aperture including a sealing member configured to seal the aperture when the fuel pump is in operation and allow fuel in the pressure accumulator device to drain into the fuel tank when the fuel pump is not in operation.
6 more elements
Dependencies are inferred from the claim text.