US 5,884,597 A · Fuel feeding apparatus for internal combustion engine and vehicle using the fuel feeding apparatus

Abstract

A fuel feeding apparatus includes a pressure increasing piston system, in addition to a high pressure fuel pump, for further increasing the fuel pressure at the outlet of the high pressure fuel pump. For this purpose, a first piston provided in a first cylinder is moved in response to the pressure of fuel drawn up from a fuel tank and fed to the high pressure pump by a low pressure fuel feed pump, and a second piston provided in a second cylinder and having a diameter smaller than the diameter of the first piston is connected to the first piston and is moved together with the first piston for pressurizing fuel in the second cylinder communicating with the outlet of the high pressure fuel pump at the time of engine starting, and before the high pressure fuel pump is started. The first and second pistons then are automatically returned to their initial positions, respectively, after high pressure fuel pump is started, while the pressure of the highly pressurized fuel in the high pressure fuel pipe is maintained by a high pressure regulator, by designing the first and second cylinders, including the relative sizes of the respective pistons, so that a possible maximum pressure to which the fuel is increased by the piston system is set to a value lower than a preset high pressure value to be attained by the high pressure fuel pump.

Claims14

Dependent claims

A fuel feeding apparatus for an internal combustion engine, comprising:

a low pressure fuel feed pump for pressurizing and transferring fuel from a fuel tank;
a high pressure fuel pump, whose operation is started subsequently to that of said low pressure fuel feed pump at the time of engine starting, for more highly pressurizing said fuel transferred by said low pressure fuel feed pumps, in comparison with the pressure of said transferred fuel, and for feeding said more highly pressurized fuel to a high pressure fuel pipe;
pressure increasing means, provided in addition to said high pressure fuel pump, for increasing the pressure of fuel in said high pressure fuel pipe at the time of initiation of engine starting and before said high pressure fuel pump is started;
means for maintaining a preset high pressure value to be attained by said high pressure fuel pump in said high pressure fuel pipe after said engine is stopped subsequently to starting and for returning an operational state of said pressure increasing means to an initial state, which it was in before engine starting was initiated, when said high pressure fuel pump is started;
and
a plurality of injection valves, connected to said high pressure fuel pipe, for injecting said fuel, which is highly pressurized to said preset high pressure value and is contained in said high pressure fuel pipe, into cylinders of said internal combustion engine.

3 more elements

A vehicle, comprising:

a fuel tank provided at a back part of a body of said vehicle;
a low pressure fuel feed pump disposed in the vicinity of or in said fuel tank;
an internal combustion engine provided at a front part of said body, including injection valves for injecting fuel into cylinders of said engine;
a high pressure fuel pump provided in the vicinity of or at said internal combustion engine, for more highly pressurizing said fuel fed from said fuel tank by said low pressure fuel feed pump through a low pressure fuel pipe, in comparison with the pressure of said fuel fed to said high pressure fuel pump;
a high pressure fuel pipe from which said fuel highly pressurized by said high pressure fuel pump is fed to each of said injection valves;
and
pressure increasing means, provided in addition to said high pressure fuel pump, for increasing the pressure of fuel in said high pressure fuel pipe at the time of initiation of engine starting and before said high pressure fuel pump is started,
wherein a preset high pressure value, attained by said high pressure fuel pump during operation thereof, is maintained at said high pressure fuel pipe after said engine is stopped subsequently to starting.

5 more elements

Dependencies are inferred from the claim text.

Fuel feeding apparatus for internal combustion engine and vehicle using the fuel feeding apparatus

Life of this patent

Fuel feeding apparatus for internal combustion engine and vehicle using the fuel feeding apparatus

Life of this patent

Abstract

Claims14