Patent ID: 8752528

Claim:
A fuel injection device comprising a fuel pump for pressurizing fuel, a solenoid valve for injecting pressurized fuel into an intake passage of an engine, a high-pressure fuel passage that extends from the fuel pump to the solenoid valve and has a medially positioned constant-pressure chamber for adjusting the fuel to a predetermined pressure, and a fuel return passage connected to a fuel return pipe, with the fuel return passage extending from the constant-pressure chamber and having a medially positioned priming pump, wherein: the constant-pressure chamber is configured with a top wall disposed above an opening of the high-pressure fuel passage opposite the solenoid valve, the fuel return passage opens into an upper space adjacent the top wall at a position above the opening of the high-pressure fuel passage, and a gas accumulating in the constant-pressure chamber is discharged from the upper space toward a fuel tank via the fuel return passage.