An electronically controlled fuel injection device that achieves reduced component count, simplified construction, and cost reduction while promoting discharge of vapor that is generated in a pressurizing chamber. With a fuel passage from a fuel intake pipe into a pressurizing chamber and a return passage that is a discharge passage for vapor generated in the pressurizing chamber, and a plunger with a prescribed reciprocating operation having a standby position set as a position enabling fuel supply and vapor discharge, the electronically controlled fuel injection device eliminates the need for an inlet check valve and promotes the discharge of vapor that is generated when fuel is supplied from the fuel intake pipe to the pressurizing chamber.

The present invention relates to a fuel pump for pumping fuel, comprising a piston (2) and a diaphragm seal element (3), which seals on an inner annular seal seat (4) and an outer annular seal seat (5), wherein the following equation is satisfied: (Ra.sup.2−ra.sup.2)/(ri+L).sup.2=ra/ri, where ri is the inner radius of the inner seal seat (4), ra is the inner radius of the outer seal seat (5), Ra is the outer diameter of the piston (2) and L is a difference between an outer radius (Ria) of the inner seal seat (4) and the inner radius (ri) of the inner seal seat (4). The invention further relates to a method for operating a fuel pump.

A vehicle and a method of reducing sound produced by a liquid fluid pump are disclosed. A pump is activated when a predetermined event is detected. A control valve of the pump is operated in one of an initial and a standard mode when the pump is activated. The control valve is operable to allow a gaseous fluid to vent out of the pump when in the initial mode corresponding to the pump being in a first phase. The control valve is operable to allow a liquid fluid to move through the pump when in the standard mode corresponding to the pump being in a second phase. A solenoid of the control valve is energized and de-energized, at a calibrated frequency, in a sequence when in the initial mode to reduce the sound in the pump during the initial mode.

A vehicle and a method of reducing sound produced by a liquid fluid pump are disclosed. A pump is activated when a predetermined event is detected. A control valve of the pump is operated in one of an initial and a standard mode when the pump is activated. The control valve is operable to allow a gaseous fluid to vent out of the pump when in the initial mode corresponding to the pump being in a first phase. The control valve is operable to allow a liquid fluid to move through the pump when in the standard mode corresponding to the pump being in a second phase. A solenoid of the control valve is energized and de-energized, at a calibrated frequency, in a sequence when in the initial mode to reduce the sound in the pump during the initial mode.

A fuel pump for a liquid fuel injection system of a motor vehicle is provided. The fuel pump for a fuel injection system includes a low-pressure pump that provides liquid fuel from a fuel tank of the motor vehicle at a low pressure. A high-pressure pump in fluid communication with the low-pressure pump and compresses the liquid fuel from the low pressure to a high pressure for injecting the liquid fuel into an internal combustion engine of the motor vehicle. A pump drive drives the low-pressure pump and the high-pressure pump synchronously with a pump frequency independently from an engine speed of the internal combustion engine of the motor vehicle.

A fuel pump for a liquid fuel injection system of a motor vehicle is provided. The fuel pump for a fuel injection system includes a low-pressure pump that provides liquid fuel from a fuel tank of the motor vehicle at a low pressure. A high-pressure pump in fluid communication with the low-pressure pump and compresses the liquid fuel from the low pressure to a high pressure for injecting the liquid fuel into an internal combustion engine of the motor vehicle. A pump drive drives the low-pressure pump and the high-pressure pump synchronously with a pump frequency independently from an engine speed of the internal combustion engine of the motor vehicle.

A fuel supplying device is provided with a supplemental fuel chamber such that there is no delay in the supply of fuel during high-speed operation. The fuel supplying device comprises: an outlet pipe in communication with a fuel injecting nozzle equipped in an intake manifold of an engine or an air intake passage of a carburetor; a pressing member configured to undergo reciprocating motion synchronized with the rotational period of an engine; a fuel chamber configure to supply fuel to an intake manifold of the engine from the fuel injecting nozzle through cooperation of the reciprocating motion of the pressing member, wherein the inlet check valve and the outlet check valve are configured to open and close alternatingly; and a fuel reservoir having a prescribed volume is connected and disposed upstream of the inlet check valve in the inlet pipe.

A fuel supplying device is provided with a supplemental fuel chamber such that there is no delay in the supply of fuel during high-speed operation. The fuel supplying device comprises: an outlet pipe in communication with a fuel injecting nozzle equipped in an intake manifold of an engine or an air intake passage of a carburetor; a pressing member configured to undergo reciprocating motion synchronized with the rotational period of an engine; a fuel chamber configure to supply fuel to an intake manifold of the engine from the fuel injecting nozzle through cooperation of the reciprocating motion of the pressing member, wherein the inlet check valve and the outlet check valve are configured to open and close alternatingly; and a fuel reservoir having a prescribed volume is connected and disposed upstream of the inlet check valve in the inlet pipe.

A fuel pump for a liquid fuel injection system of a motor vehicle is provided. The fuel pump for a fuel injection system includes a low-pressure pump that provides liquid fuel from a fuel tank of the motor vehicle at a low pressure. A high-pressure pump in fluid communication with the low-pressure pump and compresses the liquid fuel from the low pressure to a high pressure for injecting the liquid fuel into an internal combustion engine of the motor vehicle. A pump drive drives the low-pressure pump and the high-pressure pump synchronously with a pump frequency independently from an engine speed of the internal combustion engine of the motor vehicle.

A fuel pump for a liquid fuel injection system of a motor vehicle is provided. The fuel pump for a fuel injection system includes a low-pressure pump that provides liquid fuel from a fuel tank of the motor vehicle at a low pressure. A high-pressure pump in fluid communication with the low-pressure pump and compresses the liquid fuel from the low pressure to a high pressure for injecting the liquid fuel into an internal combustion engine of the motor vehicle. A pump drive drives the low-pressure pump and the high-pressure pump synchronously with a pump frequency independently from an engine speed of the internal combustion engine of the motor vehicle.