This fuel pressure accumulating device comprises: a fuel pressure accumulating unit inside which a pressure accumulating space is provided; a fuel inflow unit which is fitted to the fuel pressure accumulating unit and through which fuel can flow into the pressure accumulating space; a fuel outflow unit which is fitted to the fuel pressure accumulating unit and through which the fuel can flow from the pressure accumulating space; and a fuel storage unit which is provided in the fuel pressure accumulating unit, and which stores fuel that has leaked to a position in the fuel pressure accumulating unit where the fuel inflow unit is fitted, and a position in the fuel pressure accumulating unit where the fuel outflow unit is fitted.

A method for fuelling an internal combustion engine, and a fuel system (10) for delivering a variety of fuel types to the engine, with selected fuel types typically being chosen according to theft availability. The fuel system (10) can be configured to accommodate liquid fuels such as gasoline, ethanol or a blend thereof, and gaseous fuels such as CNG, LNG or LPG. The engine is configured to operate on any of the designated liquid fuels, and can switch between the liquid and gaseous fuels. The fuel system (10) includes a respective common delivery arrangement (11) for selectively delivering fuel into the combustion chamber of each cylinder of the engine. The common delivery arrangement (11) comprises at a fluid delivery device (12) and a liquid metering device (31) configured for operation in concert. The fluid delivery device (12) comprises a fluid delivery injector. Fuel is delivered to each combustion chamber is through the same fluid delivery device; that is, the same fluid delivery device (12) is used, regardless of the fuel type. More particularly, the fluid delivery device (12) can be used for delivery of gaseous fuel only, delivery of liquid fuel only (by way of an air assist delivery process), or delivery of a fuel mixture comprising the gaseous fuel and the liquid fuel according to the fuelling requirements of the engine at any time.

Methods and systems are providing for improving zero flow lubrication (ZFL) of a high pressure fuel pump coupled to direct fuel injectors via a direct injection fuel rail. A ZFL transfer function for the fuel pump is learned while fuel is at non-nominal fuel bulk modulus conditions and corrected for variations from a nominal fuel bulk modulus estimate. When zero flow lubrication of the pump is requested, the pump is operated with a duty cycle based on the learned transfer function and an instantaneous estimate of the fuel bulk modulus to compensate for differences in fuel condition from the nominal fuel bulk modulus estimate.

The invention relates to a fuel supply device for supplying fuel to a first injection device of an internal combustion engine, in particular of a motor vehicle, having at least one first low-pressure port, via which the fuel can be fed to the high-pressure fuel pump from a low-pressure fuel pump, having at least one second low-pressure port for conducting the fuel conveyed by means of the low-pressure fuel pump and fed to the high-pressure fuel pump away from the high-pressure fuel pump to a second injection device provided in addition to the first injection device, having a pump housing as first structural element, and having a second structural element, which is formed separately from the pump housing and which is held on the pump housing, wherein both low-pressure ports are arranged on one of the structural elements.

Methods and systems are provided for pressurizing a step chamber of a direct injection fuel pump. In one example, the step chamber may be pressurized to a pressure higher than an output pressure of a lift pump, the lift pump supplying fuel to the direct injection fuel pump. The pressurization of the step chamber may occur during at least a portion of a pump stroke of the direct injection fuel pump.

Methods and systems are provided for reducing fueling errors resulting from pressure pulsations in a port injection fuel rail. The pressure pulsations result from pressure pulsations generated in a high pressure fuel pump delivering fuel to both the port injection fuel rail and a direct injection fuel rail. A center of a port injection fuel pulse is repositioned on a nearest fuel rail pressure sampling point in the advanced direction to improve the accuracy of the delivered fuel pulse.

The invention relates to a high-pressure fuel pump for supplying fuel to a first injection device of an internal combustion engine, in particular of a motor vehicle, having at least one first low-pressure port, via which the fuel can be fed to the high-pressure fuel pump from a low-pressure fuel pump for conveying the fuel, having at least one low-pressure chamber, to which at least a part of the fuel fed to the high-pressure fuel pump via the first low-pressure port can be fed, having at least one second low-pressure port, for conducting the fuel conveyed by means of the low-pressure fuel pump and fed to the high-pressure fuel pump away from the high-pressure fuel pump to a second injection device provided in addition to the first injection device.

Various methods and systems are provided for health assessments of a fuel system. In one example, a fuel system includes a high-pressure fuel pump operable to increase fuel pressure from a first pressure to a second pressure, a common fuel rail fluidly coupling the high-pressure fuel pump to a plurality of fuel injectors each of which is operable to inject fuel to individual cylinders of an engine, a pressure sensor operable to detect a pressure of fuel at the common fuel rail, and a controller operable to diagnose a condition of the high-pressure fuel pump based on output from the pressure sensor.

A fuel system includes a low-pressure fuel delivery unit; a high-pressure fuel delivery unit which has a drive region and a delivery region such that the drive region supplies fuel to the delivery region and such that the delivery region supplies fuel to a high-pressure fuel injector; a low-pressure fuel supply passage which supplies fuel from the low-pressure fuel delivery unit to the drive region of the high-pressure fuel delivery unit; a cooling passage which receives fuel from the drive region of the high-pressure fuel delivery unit; and a low-pressure fuel injector supply passage which is in direct fluid communication with the low-pressure fuel supply passage and which supplies fuel to a low-pressure fuel injector from the cooling passage.

An internal combustion engine (1) has a plurality of combustion cylinders at each of which a fuel injection device (120) is provided. Every combustion cylinder is provided with its own pilot unit (10c-10f) with a fuel accumulator which is integrated therein and which is connected by one of a plurality of first fuel lines (110) to the fuel injection device associated with the respective combustion cylinder for supplying fuel to the latter. A fuel pump which can be connected to a fuel source for supplying a predetermined fuel pressure is integrated in at least one of the pilot units (10d). The fuel accumulator of every pilot unit is so adapted that it ensures that fuel delivered by the fuel pump is supplied to the respective associated fuel injection device in a pressure-stable manner.