US 8,291,889 B2 · Pressure control in low static leak fuel system

Abstract

A pressure relief valve includes a valve body having a valve seat fluidly positioned between an inlet and an outlet. A valve member is movable among a first position, a second position, and a third position. The valve member is in contact with the valve seat and fluidly blocks the inlet from the outlet at the first position. At the second position of the valve member, the inlet is fluidly connected to the outlet via a small flow area. The inlet is fluidly connected to the outlet via a large flow area when the valve member is at the third position. An electrical actuator is attached to the valve body and is operably coupled to move the valve member when energized. The valve member includes an opening hydraulic surface exposed to fluid pressure in the inlet when at the first position. A spring is operably positioned to bias the valve member toward the second position when the valve member is at the third position.

Claims14

Dependent claims

A pressure relief valve, comprising:

a valve body having a valve seat fluidly positioned between an inlet and an outlet;
a valve member being movable among a first position, a second position, and a third position;
the valve member being in contact with the valve seat and fluidly blocking the inlet from the outlet at the first position;
the inlet being fluidly connected to the outlet via a small flow area when the valve member is at the second position;
the inlet being fluidly connected to the outlet via a large flow area when the valve member is at the third position;
an electrical actuator attached to the valve body and being operably coupled to move the valve member when energized;
the valve member having an opening hydraulic surface exposed to fluid pressure in the inlet when at the first position;
and
a first spring operably positioned to bias the valve member toward the second position when the valve member is at the third position.

6 more elements

An engine system, comprising:

a low static leak fuel system that includes:
a common rail;
a plurality of fuel injectors fluidly connected to the common rail via individual branch passages;
a variable delivery high-pressure pump with an outlet fluidly connected to an inlet of the common rail;
a fuel tank;
a fuel transfer pump with an inlet fluidly connected to the fuel tank, and an outlet fluidly connected to an inlet of the variable delivery high-pressure pump;
a pressure relief subsystem including an electrical actuator, and the pressure relief subsystem having a first configuration, a second configuration, and a third configuration, and fluid communication between the common rail and the fuel tank being closed in the first configuration, and the common rail being in fluid communication with the fuel tank via a small flow area in the second configuration, and the common rail being in fluid communication with the fuel tank via a large flow area in the third configuration, and the pressure relief subsystem being hydraulically moved from the first configuration to the third configuration responsive to fluid pressure in the common rail exceeding a predetermined pressure that is greater than a predetermined maximum operating pressure of the fuel system;
and
an electronic controller in individual control communication with each of the pressure relief subsystem, the variable delivery high-pressure pump and the plurality of fuel injectors, and the electronic controller being configured to communicate a pressure decay control signal to the electrical actuator to move the pressure relief subsystem from the first configuration to the second configuration and then back to the first configuration responsive to an engine load reduction determination.

6 more elements

Dependencies are inferred from the claim text.

Pressure control in low static leak fuel system

Life of this patent

Pressure control in low static leak fuel system

Life of this patent

Abstract

Claims14