Backpressure valve and fuel system having the same
AssigneeDenso Corporation
InventorJun KONDOH
Life of this patent
Estimating the term…
Abstract
A return fuel passage is configured to communicate an outlet of a low-pressure fuel pump with a back pressure side of a fuel injection device. The return fuel passage is configured to partially return fuel from the back pressure side to the fuel tank to control fuel pressure at the back pressure side in response to fuel injection. In a starting operation a backpressure control valve communicates the outlet of the low-pressure fuel pump with the back pressure side and blocks the fuel tank from both the outlet of the low-pressure fuel pump and the back pressure side. In a normal operation, the backpressure control valve communicates the back pressure side with the fuel tank and blocks the outlet of the low-pressure fuel pump from both the fuel tank and the back pressure side.
Claims10
A backpressure control valve for a low-pressure fuel system having a return fuel passage, which is configured to communicate an outlet of a low-pressure fuel pump, which is for drawing fuel from a fuel tank, with a back pressure side of a fuel injection device, the return fuel passage configured to partially return pressurized fuel from the back pressure side to the fuel tank and control fuel pressure at the back pressure side in response to fuel injection from the fuel injection device to an internal combustion engine, the backpressure control valve comprising:
- a switching unit configured to control communication between the outlet of the low-pressure fuel pump and the back pressure side, communication between the back pressure side and the fuel tank, and communication between the outlet of the low-pressure fuel pump and the fuel tank,
- wherein in a starting operation:
- the switching unit communicates the outlet of the low-pressure fuel pump with the back pressure side;
- the switching unit blocks the outlet of the low-pressure fuel pump from the fuel tank;
- and
- the switching unit blocks the back pressure side from the fuel tank,
- wherein in a normal operation:
- the switching unit communicates the back pressure side with the fuel tank;
- the switching unit blocks the outlet of the low-pressure fuel pump from the fuel tank;
- and
- the switching unit blocks the outlet of the low-pressure fuel pump from the back pressure side.
Dependencies are inferred from the claim text.