摘要:
A high pressure fuel pump having a variable fuel injection rate, including a pump body, a pump cylinder formed in the pump body and a piston reciprocable within the pump cylinder, which defmes a pressurization chamber (120). The pump piston (106) has a reduced diameter portion which provides a primary piston (112). A piston annulus is slidably mounted thereon and provides a secondary piston (116). An annular actuation chamber (122) adjoins the secondary piston (116) opposite the pressurization chamber (120). An actuation passage is provided between a return fuel drain and the actuation chamber (122), which is selectively open or closed passively by pump piston (106) movement and/or dynamically by operation of an actuation solenoid valve (128). If the actuation chamber passage (124) is open, then during the pressurization stroke the secondary piston (116) will remain stationary relative to the pump body, but if it is closed then the secondary piston (116) must stroke in unison with the primary piston (112).
摘要:
A high pressure fuel pump having a variable fuel injection rate, including a pump body, a pump cylinder formed in the pump body and a piston reciprocable within the pump cylinder, which defines a pressurization chamber (120). The pump piston (106) has a reduced diameter portion which provides a primary piston (112). A piston annulus is slidably mounted thereon and provides a secondary piston (116). An annular actuation chamber (122) adjoins the secondary piston (116) opposite the pressurization chamber (120). An actuation passage (124) is provided between a return fuel drain and the ctuation chamber (122), which is selectively open or closed passively by pump piston (106) movement and/or dynamically by operation of an actuation solenoid valve (128). If the actuation chamber passage (124) is open, then during the pressurization stroke the secondary piston (116) will remain stationary relative to the pump body, but if it is closed then the secondary piston (116) must stroke in unison with the primary piston (112).
摘要:
A dual mode fuel injector having first (15) and second (30) valve members. The valve members are actuatable independently of one another and are arranged to open in opposite directions. The valve members control the flow through first (18) and second (29) orifices, one of which injects the fuel at a narrow angle with respect to the injector axis, and the other of which injects the fuel at a wider angle with respect to this axis.
摘要:
A fuel injection system for supplying pressurised fuel to a fuel injector (50), the fuel injection system comprising an accumulator volume (59) for supplying fuel at a first injectable pressure level (P1) to the fuel injector (50) through a fuel supply passage (52), pump means (63) for increasing the pressure of fuel supplied to the injector (50) to a second injectable pressure level (P2), and valve means (62, 162, 262, 362) operable between a first position in which fuel at the first injectable pressure level (P1) is supplied to the injector (50) and a second position in which communication between the injector (50) and the accumulator volume (59) is broken so as to permit fuel at the second injectable pressure (P2) to be supplied to the injector. The injection system may include valve means in the form of a three-position valve (262) or may include a shut off valve (464; 1464) for controlling the supply of fuel through the fuel supply passage (52).
摘要:
A fuel injection system for supplying pressurised fuel to a fuel injector (50), the fuel injection system comprising an accumulator volume (59) for supplying fuel at a first injectable pressure level (P1) to the fuel injector (50) through a fuel supply passage (52), pump means (63) for increasing the pressure of fuel supplied to the injector (50) to a second injectable pressure level (P2), and valve means (62, 162, 262, 362) operable between a first position in which fuel at the first injectable pressure level (P1) is supplied to the injector (50) and a second position in which communication between the injector (50) and the accumulator volume (59) is broken so as to permit fuel at the second injectable pressure (P2) to be supplied to the injector. The injection system may include valve means in the form of a three-position valve (262) or may include a shut off valve (464; 1464) for controlling the supply of fuel through the fuel supply passage (52).
摘要:
A shut off valve for use in a fuel injection system including an injector, the shut off valve control valve (462) including a shut off valve member (464, 1464) that is operable between open and closed operating positions to control the supply of fuel to the injector (50), the shut off valve member (464, 1464) having a surface exposed to fuel pressure within a shut off control chamber (157), the shut off valve further comprising a control valve (11) for controlling fuel pressure within the shut off valve control chamber (157), thereby to control movement of the shut off valve member (464, 1464) between the open and closed operating positions.
摘要:
A fuel system for use in an internal combustion engine, particularly of the type provided with an after treatment device for reducing emissions levels, comprises a fuel pump (10) having a pumping cycle during which fuel is pressurized to a high level within a pumping chamber for delivery to an injector (14). The injector (14) is arranged to provide a primary fuel injection event, and a secondary fuel injection event within the same pumping cycle, in use. The injector (14) includes a valve needle (16) which is engageable with a valve needle seating to control fuel delivery through an injector (14) and injection control valve means for controlling movement of the valve needle (16) so as to control the primary and secondary fuel injection events. The primary injection event may be a main injection of fuel, and the secondary injection event may be a late-post injection of fuel for regeneration of the after treatment device. Engine having an after treatment device.
摘要:
A high pressure fuel pump having a variable fuel injection rate, including a pump body, a pump cylinder formed in the pump body and a piston reciprocable within the pump cylinder, which defines a pressurization chamber (120). The pump piston (106) has a reduced diameter portion which provides a primary piston (112). A piston annulus is slidably mounted thereon and provides a secondary piston (116). An annular actuation chamber (122) adjoins the secondary piston (116) opposite the pressurization chamber (120). An actuation passage (124) is provided between a return fuel drain and the ctuation chamber (122), which is selectively open or closed passively by pump piston (106) movement and/or dynamically by operation of an actuation solenoid valve (128). If the actuation chamber passage (124) is open, then during the pressurization stroke the secondary piston (116) will remain stationary relative to the pump body, but if it is closed then the secondary piston (116) must stroke in unison with the primary piston (112).
摘要:
A dual mode fuel injector having first (15) and second (30) valve members. The valve members are actuatable independently of one another and are arranged to open in opposite directions. The valve members control the flow through first (18) and second (29) orifices, one of which injects the fuel at a narrow angle with respect to the injector axis, and the other of which injects the fuel at a wider angle with respect to this axis.