Abstract:
A fuel injector for use in an internal combustion engine, the fuel injector comprising a valve member that is moveable with in a bore of an injection nozzle so as to be engageable with a valve seat region to control fuel delivery through one or more nozzle outlets, an injector body housing an actuator that is operable to move the valve member within the bore, and defining an accumulator volume for storing high pressure fuel. The invention is characterised in that the fuel injector includes a damping chamber in fluid communication with the accumulator volume through a fluid passage, the damping chamber serving to reduce pressure wave activity within the accumulator volume.
Abstract:
A fuel injector (100) for use in an internal combustion engine comprising an injection nozzle (118) having a nozzle body (120) provided with a nozzle bore (130), a first valve needle (136) received within the nozzle bore and being engageable with a first seat region (137) to control fuel delivery through a first set of nozzle outlets (126), and a second valve needle (138) received within a valve bore (140) provided in the first valve needle and being engageable with a second seat region (144) arranged to control fuel delivery through a second set of nozzle outlets (128). A control chamber (184) for fuel is provided, preferably at least in part, between the first valve needle and the second valve needle, wherein movement of the first valve needle is responsive to fuel pressure in the control chamber, and wherein movement of the second valve needle is mechanically coupled to an armature of the first actuator arrangement (159), such that when the second valve needle lifts away from the second seating region, a fuel flow path is established between the control chamber and the second set of nozzle outlets. The fuel injector further includes a second actuator arrangement (200) that is operable to control fuel flow into the control chamber thereby regulating fuel pressure within the control chamber and, thus, movement of the first valve needle.
Abstract:
An inlet valve assembly (14) for a high-pressure fuel pump is disclosed. The inlet valve assembly comprises an inlet valve member (28) moveable between open and closed positions to control the fuel flow from a source (24) of low-pressure fuel to a pumping chamber (16) of the fuel pump, and an electromagnetic actuator (50) comprising a core member (52), a solenoid coil (54), and an armature (58) moveable towards the core member (52) in response to energisation of the coil (54). In a first phase of operation, the armature (58) is decoupled from the valve member (28) to allow movement of the armature (58) towards the core member (52) without movement of the valve member (28) and, in a second phase of operation, the armature (58) is coupled to the valve member (28) to carry the valve member (28) towards its closed position. Because the armature (58) is initially decoupled from the valve member (28), variations in concentricity and part dimensions due to manufacturing tolerances can be accommodated without affecting operation of the valve assembly.
Abstract:
The present invention relates to an injection pump system (1). An injection pump (3) is provided for supplying high pressure fuel. A low pressure fuel line (5) is provided in fluid communication with an inlet of the injection pump (3). A high pressure fuel line (7) is provided in fluid communication with an outlet of the injection pump (3) and a fuel rail. A control valve (27) is provided for controlling filling of the injection pump (3). The injection pump system is provided with a control unit for controlling operation of the control valve (27). The control unit is configured to close the control valve (27) to inhibit the supply of fuel to the injection pump when the rail pressure is within a target pressure range. The invention also relates to a method of operating an injection pump system. An aspect of the invention also relates to a fuel injection system.
Abstract:
A pump head for a fuel pump for use in a common rail fuel injection system is provided. The pump head (100; 200; 300) comprises a pump head housing (102; 202; 302), a pumping chamber (106; 206; 306) defined within the pump head housing (102; 202; 302), and an inlet valve arrangement (108; 208; 308) for controlling fuel flow into the pumping chamber (106; 206; 306), the inlet valve arrangement (108; 208; 308) including an inlet valve member (110; 210; 310) moveable between open and closed positions wherein, in use, movement of the inlet valve member (110; 210; 310) is damped by means of viscoelastic damping.
Abstract:
The invention relates to an assembly (30) for an electrically operated valve (34) in the automotive field aimed to increase the injection pressure of fuel distributed to combustion chambers, said assembly (30) comprising both a coil unit (32), wherein a solenoid (33) can control the movements of the electrically operated valve (34) in a housing along a given axis (36), and an hydraulic unit (35) to provide fuel at the injection pressure, a clip ring (38) being located into a cavity of the coil unit (32) and a cavity of the hydraulic unit (35) to maintain the coil unit (32) and the hydraulic unit (35) associated. The invention is characterized in that the coil unit (32) presents a plurality of slots (46) providing access to the clip ring (38), across the coil unit, from the exterior of the assembly.