In a hybrid fuel supply system for the same high pressure supply pump used for gasoline direct injection (DI) is also used to supply the port injection (PI) system. For a given pumping stroke, fuel can be delivered only to the DI system, only to the PI system, or a first portion can be delivered to the DI system and a second portion delivered to the PI system. The pumping chamber always fills to maximum volume. Fuel metering for DI is by a control valve, which when closed delivers fuel into the DI system and when opened spills pumped fuel into the PI system. Any spill at high pressure opens a pressure regulating valve in the PI system that dumps fuel at excess pressure to a low pressure region to maintain the PI system at a constant target pressure.

A fuel injection control device includes processing circuitry, which executes an estimating process to estimate pressure in first and second fuel storage members connected to first and second fuel injection valves. The estimating process includes: estimating the pressure in the first fuel storage member based on a detection value of a pressure sensor that detects the pressure in the first fuel storage member and a cycle of pulsation in the first fuel storage member, which is determined in accordance with an interval of fuel injections in a first bank; and estimating the pressure in the second fuel storage member by assuming that a phase of a periodic fluctuation of the pressure in the second fuel storage member and a phase of a periodic fluctuation of the pressure in the first fuel storage member are in antiphase.

An engine (21) including a main fuel injection valve (79), a pilot fuel injection valve (82), a liquid fuel supply rail pipe (42), and a pilot fuel supply rail pipe (47). The main fuel injection valve (79) supplies liquid fuel from the liquid fuel supply rail pipe (42) to a combustion chamber (110) during combustion in a diffusion combustion system. The pilot fuel injection valve (82) supplies pilot fuel from the pilot fuel supply rail pipe (47) to the combustion chamber (110) in order to ignite gaseous fuel during combustion in a premixed combustion system. The liquid fuel supply rail pipe (42) is disposed at one side of an imaginary vertical plane (P1) including an axis of a crank shaft. The pilot fuel supply rail pipe (47) is disposed at the side of the imaginary vertical plane (P1) at which the liquid fuel supply rail pipe (42) is disposed.

The invention relates to a fuel supply system for an internal combustion engine comprising:a low pressure fuel pump (18);a low pressure supply circuit (34) through which fuel is delivered by the low pressure pump (18) to one or several high pressure circuits (16), said low pressure supply circuit (34) comprising at least one delivery connection (36) for delivering fuel to the high pressure circuit(s) (16);a pressure regulator (54) through which excess fuel from the low pressure supply circuit (34) is discharged through the pressure regulator (54) in a pump return circuit (56) which is fluidically connected to an input (20) of the low pressure pump (18) without passing through the fuel tank (14); characterized in that the pressure regulator (54) is located downstream of the delivery connection (36), and in that a fuel derivation circuit (60) is fluidically connected to the low pressure fuel supply circuit (34) downstream of the at least one delivery connection (36) to the high pressure circuit(s) and upstream of the pressure regulator (54).

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 positioned on an average pressure-crossing of the pressure pulsations so as to cancel out the effect of the over-average and under-average pressure pulsations.

An electronic control unit is configured to switch a drive mode of a first high-pressure fuel pump and a second high-pressure fuel pump, in accordance with an operating state of an internal combustion engine, either to a twin-drive mode, in which both the first high-pressure fuel pump and the second high-pressure fuel pump are driven, or to a single-drive mode, in which either one of the first high-pressure fuel pump and the second high-pressure fuel pump is driven. The electronic control unit is configured to determine whether or not a pump ambient temperature, which is the ambient temperature of the first high-pressure fuel pump and the second high-pressure fuel pump, is equal to or higher than a predetermined first temperature. In a case where the pump ambient temperature is equal to or higher than the first temperature, the electronic control unit turns ON a twin-drive mode request flag.

In a hybrid fuel supply system for the same high pressure supply pump used for gasoline direct injection (DI) is also used to supply the port injection (PI) system. For a given pumping stroke, fuel can be delivered only to the DI system, only to the PI system, or a first portion can be delivered to the DI system and a second portion delivered to the PI system. The pumping chamber always fills to maximum volume. Fuel metering for DI is by a control valve, which when closed delivers fuel into the DI system and when opened spills pumped fuel into the PI system. Any spill at high pressure opens a pressure regulating valve in the PI system that dumps fuel at excess pressure to a low pressure region to maintain the PI system at a constant target pressure.

A control device for an internal combustion engine is equipped with an electronic control unit. The electronic control unit is configured to: i) calculate amplitudes of respective waves, respectively, originating from a plurality of factors that causes fuel pressure pulsation within a low-pressure fuel passage, vibration frequencies of the respective waves within a crank angle range of 360 degrees, initial phases of the respective waves, and central fuel pressure values of the respective waves; and ii) predict a fuel pressure value at an arbitrary crank angle according to a model formula showing a synthesized wave obtained by synthesizing the respective waves, on a basis of the amplitudes, the vibration frequencies, the initial phases, and the central fuel pressure values of the respective waves calculated.

A valve device is provided between a high-pressure pump and a fuel tank. A first valve member, an intermediate member and a second valve member are accommodated in a valve housing. The first valve member, which is arranged on a downstream side of the intermediate member, is biased by a first spring in a direction to a first valve seat formed in the intermediate member. The second valve member, which is arranged on an upstream side of the intermediate member, is biased by a second spring in a direction to a second valve seat formed in the intermediate member. When the first valve member is separated from the first valve seat, fuel flows in a forward direction from an upstream-side fuel passage to a downstream-side fuel passage. When the second valve member is separated from the second valve seat, the fuel flows in a reverse direction.

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.