Patent ID: 7493897

Claim:
A fuel supply apparatus for an internal-combustion engine, the apparatus supplying fuel stored in a fuel tank to an injection valve of the internal-combustion engine through a fuel supply passage and a fuel pump disposed in the fuel supply passage and comprising: a component adjustment unit for adjusting component composition of fuel by separating a particular component from fuel, the component adjustment unit provided in a portion of the fuel supply passage near the injection valve, wherein: the component adjustment unit includes a component separation wall, which divides an interior of the portion of the fuel supply passage between an anterior chamber and a posterior chamber; the anterior chamber has a fuel inlet, and fuel, the particular component of which is yet to be separated, flows into the anterior chamber through the fuel inlet from the fuel pump; and the component separation wall includes a separation membrane, which the particular component of fuel in the anterior chamber selectively permeates to be separated, and a porous substrate, which supports the separation membrane, wherein the particular component after passing through the component separation wall is temporarily stored in the posterior chamber; a low-pressure side passage that connects the posterior chamber and the fuel tank; and a valve disposed in the low-pressure side passage to one of open and close the low-pressure side passage, wherein: when the low-pressure side passage is opened by the valve, the particular component of fuel in the anterior chamber is separated while passing through the component separation wall and stored in the posterior chamber, and fuel, from which the particular component is separated, is supplied to the injection valve from the anterior chamber; and when the low-pressure side passage is closed by the valve, the separation of the particular component from fuel is restricted, so that fuel, the particular component of which is not separated, is supplied to the injection valve.