A returnless fuel system includes a fuel injector, an accumulator, a first fuel pump assembly and a second fuel pump assembly. The accumulator is adapted to store pressurized fuel that is utilized by the fuel injector during prescribed conditions. The first fuel pump assembly is adapted to supply the pressurized fuel at a controlled pressure to the fuel injector. The second fuel pump assembly is in fluid communication with the accumulator and the first fuel pump assembly, and is adapted to provide the pressurized fuel at a controlled pressure to the first fuel pump assembly and the accumulator.

A fuel return device includes a fuel collector and a return system. The fuel collector is located in a passage between a fuel tank and a vapor fuel processing device that processes vapor fuel discharged from the fuel tank. The fuel collector collects the fuel and stores the collected fuel as a storage fuel. The return system extends from the fuel collector, and is connected to a low-pressure generation part that generates a low pressure by a flow of fuel refueled through a filler pipe into the fuel tank, to return the storage fuel to the fuel tank.

A filter arrangement for liquids has a filter housing and a functional carrier arranged inside the filter housing. A cylindrical filter element is inserted axially into the filter housing and defines an unfiltered side and a filtered side inside the filter housing. A non-return diaphragm is secured within the filter housing, wherein the non-return diaphragm is arranged on the functional carrier so as to effect an axial and/or radial sealing action of the unfiltered side relative to the filtered side of the filter arrangement.

A fuel pressure regulator includes a housing having a housing bore and a housing inlet; a piston located within the housing bore such that the piston and the housing bore define an accumulation chamber and such that the piston moves between a first piston position where the accumulation chamber is minimized in volume and a second piston position where the accumulation chamber is maximized in volume, the piston having a piston bore with a piston inlet and a piston outlet and a valve seat defined therebetween; a piston spring which biases the piston toward the first piston position; a valve closure which moves between a seated position which prevents fluid communication from the piston inlet to the piston outlet and an unseated position which provides fluid communication from the piston inlet to the piston outlet; and a valve closure spring which biases the valve closure toward the seated position.

An object of the present invention is to provide a high-pressure fuel supply pump that can restrict lowering of pressure and generation of cavitation in the vicinity of a seat by providing a throttle in a relief spring holder. Accordingly, in order to achieve the above object, the present invention relates to a fuel supply pump that includes a pressurizing chamber configured to pressurize fuel, and a relief valve mechanism configured to return fuel in a discharge path on a downstream side of the discharge valve to the pressurizing chamber. The relief valve mechanism includes a relief seat configured to close a relief channel when a relief valve is seated, a relief spring configured to energize the relief valve to the relief seat, and a relief spring holder configured to hold the relief spring. In the relief spring holder, a throttle section is formed in a fuel path for returning from a relief chamber in which the relief spring is disposed to the pressurizing chamber and the channel. The above object can be achieved by the above configuration.

A valve member is movable with first and second partition member and opens and closes a first pressure chamber with respect to a return passage. The first partition member partitions the first pressure chamber from a second pressure chamber. The second partition member partitions the second pressure chamber from a third pressure chamber. The first, second, and third pressure chambers cause fuel from a fuel flow passage to flow therethrough. A switching unit switches an opening and closing state of the second pressure chamber and the third pressure chamber with respect to the fuel flow passage and the return passage.

The invention relates to a pressure regulating valve for regulating pressure in a high-pressure fuel accumulator for an internal combustion engine, comprising a valve piston (5) accommodated axially displaceably in a bore (1) in a valve housing (2), acting on a valve closing member (3) in the direction of a valve seat (4), said valve piston being connected at the end thereof facing away from the valve seat (4) to an armature (6) of a magnetic assembly (7) for actuating the pressure regulating valve, wherein the armature (6) is accommodated in an armature chamber (8) and the valve closing member (3) is accommodated in a valve chamber (9). According to the invention, the valve chamber (9) and the armature chamber (8) are hydraulically connected via at least one groove (10) and/or bore (11) formed in the valve housing (2), valve piston (5) and/or in the armature (6), as well as at least one choke point (12).

In at least some implementations, a fuel supply module includes a reservoir and a fuel pump carried by the reservoir. The reservoir may include a body and a lid that define an internal volume to contain a supply of fuel, and the reservoir may include an inlet through which fuel enters the internal volume and an outlet from which fuel is discharged from the fuel supply module. The fuel pump is carried by the reservoir and has a first inlet communicating with the internal volume to take fuel into the fuel pump from the internal volume and a second inlet spaced above the first inlet relative to the direction of the force of gravity to take fluid or vapors into the fuel pump from the internal volume. The fuel pump includes an outlet from which fluid is discharged for delivery to an engine through the reservoir outlet.

An outboard motor includes a vapor separator tank, a downstream fuel supply path, a fuel pump that discharges a fuel in the vapor separator tank into the downstream fuel supply path, a downstream bypass path, and a downstream relief valve provided in the downstream bypass path. A first end of the downstream bypass path is connected to a downstream portion that is closer to the fuel injector than is the downstream check valve in the downstream fuel supply path, and a second end of the downstream bypass path is connected to an upstream portion between the downstream check valve and the vapor separator tank in the downstream fuel supply path. The downstream relief valve opens the downstream bypass path when a fuel pressure in a downstream region that is closer to the fuel injector than is the downstream check valve in the downstream fuel supply path exceeds a first predetermined value.

Method and apparatus for adjustable fuel pressure module. In accordance with an embodiment of the present invention, an apparatus for regulating fuel pressure comprises a body configured to mate to a fuel filter housing, a spring seat assembly configured to seal an opening in the fuel filter housing according to a force applied by a pressure regulating spring acting on the spring seat assembly, and a pressure regulating spring adjusting assembly mounted to the body, configured to constrain an adjustable length of the pressure regulating spring, wherein the spring is constrained between the spring seat assembly and the pressure regulating spring adjusting assembly. A force exerted upon the spring seat assembly by the pressure regulating spring corresponds to a desirable fuel pressure. The spring seat assembly is configured to unseal the opening in the fuel filter housing responsive to a fuel pressure greater than the desirable fuel pressure.