Abstract: A high pressure fuel pump includes a pressurizing assembly where a plunger arranged in a bore translates along a main axis. The pump also includes a fuel transfer assembly having an inlet valve assembly and an outlet valve assembly. The pressurizing assembly has a pressurizing body provided with the bore and the fuel transfer assembly has a fuel transfer body within which are arranged the inlet and the outlet valve assemblies. The pressurizing body and the fuel transfer body are distinct parts fixed to each other along a sealing area.

Abstract: A high pressure fuel pump includes a pressurizing assembly where a plunger arranged in a bore translates along a main axis. The pump also includes a fuel transfer assembly having an inlet valve assembly and an outlet valve assembly. The pressurizing assembly has a pressurizing body provided with the bore and the fuel transfer assembly has a fuel transfer body within which are arranged the inlet and the outlet valve assemblies. The pressurizing body and the fuel transfer body are distinct parts fixed to each other along a sealing area.

Abstract: The present application relates to a pump unit for a fuel injection system. The pump unit has a low pressure fuel supply line and a high pressure fuel outlet. A pumping chamber having a plunger is operable to perform a pumping cycle comprising a pumping stroke and a filling stroke. The pump unit also includes an inlet valve having an inlet valve member movable between an open position for permitting the supply of fuel to the pumping chamber from the low pressure fuel supply line and a closed position for inhibiting the supply of fuel from the pumping chamber to the low pressure supply line. An outlet valve is provided in the high pressure fuel outlet. The pump unit also includes a means for latching the inlet valve member in its open position. The present application also relates to a method of operating a pump unit.

Abstract: A pump unit has an inlet valve, an outlet valve, a supply line for supplying fuel, a pumping chamber, and a plunger for pressurizing fuel in the pumping chamber. The inlet valve includes an inlet valve member movable between a first position and a second position. The inlet valve member has an aperture formed therein. The aperture provides a first fluid pathway between the pumping chamber and the supply line when the inlet valve member is in its first position, and the aperture provides a second fluid pathway between the pumping chamber and the outlet valve when the inlet valve member is in its second position.

Abstract: A fuel pressure regulation system for a compression ignition diesel engine comprises a fuel supply line connected to an inlet of a transfer pump and a transfer pressure fuel line connected between the transfer pump outlet and the high pressure fuel pump inlet. A fuel filter is positioned in the transfer pressure fuel line and a fuel spill line fluidly connects a fuel pressure regulator to the transfer pressure fuel line at a point between the transfer pump outlet and the fuel filter. A fuel return line is connected between the fuel pressure regulator and the fuel supply line, and a control fuel line is connected between the fuel pressure regulator and the transfer pressure fuel line.

Abstract: The present application relates to a pump unit for a fuel injection system. The pump unit has a low pressure fuel supply line and a high pressure fuel outlet. A pumping chamber having a plunger is operable to perform a pumping cycle comprising a pumping stroke and a filling stroke. The pump unit also includes an inlet valve having an inlet valve member movable between an open position for permitting the supply of fuel to the pumping chamber from the low pressure fuel supply line and a closed position for inhibiting the supply of fuel from the pumping chamber to the low pressure supply line. An outlet valve is provided in the high pressure fuel outlet. The pump unit also includes a means for latching the inlet valve member in its open position. The present application also relates to a method of operating a pump unit.

Abstract: A fuel pressure regulation system for a compression ignition diesel engine comprises a fuel supply line connected to an inlet of a transfer pump and a transfer pressure fuel line connected between the transfer pump outlet and the high pressure fuel pump inlet. A fuel filter is positioned in the transfer pressure fuel line and a fuel spill line fluidly connects a fuel pressure regulator to the transfer pressure fuel line at a point between the transfer pump outlet and the fuel filter. A fuel return line is connected between the fuel pressure regulator and the fuel supply line, and a control fuel line is connected between the fuel pressure regulator and the transfer pressure fuel line.

Abstract: A fuel pressure regulation system for a compression ignition diesel engine. The system comprises a fuel supply line connected to an inlet of a transfer pump and a transfer pressure fuel line connected between the transfer pump outlet and the high pressure fuel pump inlet. A fuel filter is positioned in the transfer pressure fuel line and a fuel spill line fluidly connects a fuel pressure regulator to the transfer pressure fuel line at a point between the transfer pump outlet and the fuel filter. A fuel return line is connected between the fuel pressure regulator and the fuel supply line and a control fuel line is connected between the fuel pressure regulator and the transfer pressure fuel line. The fuel pressure regulator comprises a bore within which is located a valve member moveable from a non-regulating position of the fuel pressure regulator to a regulating position of the fuel pressure regulator.

Abstract: A fuel pipe assembly for supplying fuel to a fuel injector located within a bore of an engine cylinder head comprises a tube nut for connecting the fuel pipe to the fuel injector and a securing arrangement comprising a locking nut and a deformable clamp member for securing the fuel pipe within the tube nut. The tube nut comprises a tubular member defining an axial bore to receive the fuel pipe, a distal end shaped for cooperation with the head of the fuel pipe, and a proximal end having an attachment mechanism for engaging a compatible attachment mechanism of the locking nut. The locking nut has an axial bore to receive the fuel pipe, and an attachment mechanism for engaging a compatible attachment mechanism of the tube nut. The clamp member defines a bore to receive the fuel pipe and is deformable under compression.

Abstract: A pump unit has an inlet valve, an outlet valve, a supply line for supplying fuel, a pumping chamber, and a plunger for pressurising fuel in the pumping chamber. The inlet valve includes an inlet valve member movable between a first position and a second position. The inlet valve member has an aperture formed therein. The aperture provides a first fluid pathway between the pumping chamber and the supply line when the inlet valve member is in its first position, and the aperture provides a second fluid pathway between the pumping chamber and the outlet valve when the inlet valve member is in its second position.

Abstract: A fuel pipe assembly for supplying fuel to a fuel injector located within a bore of an engine cylinder head comprises a tube nut for connecting the fuel pipe to the fuel injector and a securing arrangement comprising a locking nut and a deformable clamp member for securing the fuel pipe within the tube nut. The tube nut comprises a tubular member defining an axial bore to receive the fuel pipe, a distal end shaped for cooperation with the head of the fuel pipe, and a proximal end having an attachment mechanism for engaging a compatible attachment mechanism of the locking nut. The locking nut has an axial bore to receive the fuel pipe, and an attachment mechanism for engaging a compatible attachment mechanism of the tube nut. The clamp member defines a bore to receive the fuel pipe and is deformable under compression.

Abstract: A fuel pressure regulation system for a compression ignition diesel engine. The system comprises a fuel supply line connected to an inlet of a transfer pump and a transfer pressure fuel line connected between the transfer pump outlet and the high pressure fuel pump inlet. A fuel filter is positioned in the transfer pressure fuel line and a fuel spill line fluidly connects a fuel pressure regulator to the transfer pressure fuel line at a point between the transfer pump outlet and the fuel filter. A fuel return line is connected between the fuel pressure regulator and the fuel supply line and a control fuel line is connected between the fuel pressure regulator and the transfer pressure fuel line. The fuel pressure regulator comprises a bore within which is located a valve member moveable from a non-regulating position of the fuel pressure regulator to a regulating position of the fuel pressure regulator.

Abstract: An accumulator fuel system for an internal combustion engine having a plurality of engine cylinders, includes an accumulator fuel volume for supplying high pressure fuel to one or more of a plurality of injectors, each of which is arranged to supply fuel to an associated one of the engine cylinders. The accumulator fuel volume is integrated within an engine component, where the engine component provides a purpose other than that solely of an accumulator volume for storing high pressure fuel. The accumulator fuel volume is therefore defined in an existing engine component, to reduce part count, weight and cost. In one embodiment the accumulator fuel volume is defined within a rocker shaft of the engine and in another embodiment within the engine cylinder head.

Abstract: A passive valve assembly for controlling the flow into or out of chamber (3) through a port (4). The valve assembly comprises a valve element (5) arranged to open in the direction of flow through the port. The valve element (5) has a piston (9) which is reciprocable in a cylinder (10) containing gas. On opening of the valve, gas is compressed in a first chamber (11) of the cylinder (10), and this energy of compression is used to reverse the direction of the valve element (5) and return it to its seat.

Abstract: An accumulator fuel system for an internal combustion engine having a plurality of engine cylinders, includes an accumulator fuel volume for supplying high pressure fuel to one or more of a plurality of injectors, each of which is arranged to supply fuel to an associated one of the engine cylinders. The accumulator fuel volume is integrated within an engine component, where the engine component provides a purpose other than that solely of an accumulator volume for storing high pressure fuel. The accumulator fuel volume is therefore defined in an existing engine component, to reduce part count, weight and cost. In one embodiment the accumulator fuel volume is defined within a rocker shaft of the engine and in another embodiment within the engine cylinder head.

Abstract: A passive valve assembly for controlling the flow into or out of chamber (3) through a port (4). The valve assembly comprises a valve element (5) arranged to open in the direction of flow through the port. The valve element (5) has a piston (9) which is reciprocable in a cylinder (10) containing gas. On opening of the valve, gas is compressed in a first chamber (11) of the cylinder (10), and this energy of compression is used to reverse the direction of the valve element (5) and return it to its seat.

Abstract: A fuel injector comprises a valve needle spring biased towards a seating. The valve needle defines a thrust surface orientated such that the application of fuel under pressure thereto applies a force to the needle urging the needle away from the seating. A valve is provided to control the supply of fuel to the thrust surface.

Abstract: A fuel injector comprises a valve needle biased by a spring towards a seating. An electromagnetic actuator arrangement is operable to vary the magnitude of the biasing force applied to the needle by the spring.

Abstract: A spring assembly comprises a helical compression spring engaged between first and second spring abutments and a collar limiting movement of the second spring abutment away from the first spring abutment.

Abstract: An injector arrangement is disclosed which comprises a valve needle urged into engagement with a seating under the action of the pressure of fuel within a control chamber. A needle control valve controls communication between a source of fuel at high pressure and the control chamber, and also between the control chamber and a low pressure drain. The needle control valve includes a valve member including an end which is engageable with a surface extending in a plane normal to the axis of the valve member to close a port communicating with the low pressure drain.