摘要:
Some embodiments are directed to a valve assembly for use with a combustion engine. The valve assembly can include a valve stem having a plunger end, and a valve head having a stem portion disposed along a central axis and connected to the plunger end of the valve stem. The valve head can have a hollow interior portion defining interior floor and ceiling surfaces, and include ribs that extend between the interior floor and ceiling surfaces. The ribs can also extend radially around the central axis of the valve head from the stem portion to an outer circumference of the hollow interior portion. Additionally, the ribs can be configured such that a majority of an upper surface of each rib contacts the ceiling surface.
摘要:
A valve (100) comprises a barrel (104) having a central bore (110), an inlet (112), and an outlet (114, 116), and a spool (120) disposed for motion within the central bore, including a ball tip (128), a metering edge (130), and a bore (132). The spool is moveable between a closed position, wherein the ball tip engages a seat (142) to prevent fluid flow through the inlet and the metering edge is disposed in a lower chamber (148) of the central bore to prevent the fluid flow through the outlet, and an opened position, wherein the tip is spaced apart from the seat to permit fluid flow through the inlet and the spool bore into an upper chamber (154) of the central bore to equalize pressure on the spool, and the metering edge is disposed in a flow path of the outlet to permit fluid flow through the outlet.
摘要:
The fuel injection system comprises a fuel injector controlled by commands of a control unit. The fuel injector comprises a metering servo valve having a control chamber provided with an outlet passage that is opened/closed by an open/close element that is axially movable. The open/close element is carried by an axial guide element that is separate from an armature of an electromagnet. The open/close element is held in the closing position by a spring acting through an intermediate body. In some instances, the strokes of the open/close element and of the armature are chosen so as to eliminate, upon closing of the servo valve, the rebounds of the open/close element subsequent to the first rebound. The control unit controls a fuel injection comprising a pilot fuel injection and a main fuel injection, via two distinct electrical commands, which are spaced apart by a dwell time such as to occur in an area of reduced variation of the amount of injected fuel. Therefore, the stability of operation of the fuel injection system increases as the dwell time varies.
摘要:
A fuel injector has an injector body and a control rod, which is movable in the injector body along an axis to control the opening/closing of a nozzle that injects fuel into a cylinder of the engine; the injector body houses a metering servovalve having a control chamber, which is axially delimited by the control rod and communicates with an inlet and with a discharge channel; the metering servovalve is provided with a shutter, which slides axially on an axial guide, from which the discharge channel exits, to open and close the discharge channel and, in consequence, vary the pressure in the control chamber; the discharge channel has at least two restrictions having calibrated passage sections and arranged in series with each other to divide the pressure drop along the discharge channel.
摘要:
The invention relates to a fuel injector for injecting fuel into a combustion chamber of an internal combustion engine, in particular a common-rail injector, comprising a control valve (19) for hydraulically connecting a control chamber (13) which is operationally connected to a one or multi-part injection valve element (9) to a low pressure region (8), wherein the control valve (19) comprises a valve element (18) which is axially adjustable by an actuator and interacts with a valve seat (20) in the closed position thereof, to which an axial guide (24) for guiding the valve element (18) in the axial adjustment movement thereof is allocated. According to the invention, a center point (M) of an imaginary circle (26) is arranged within the axial guide length of the guide (24) and the circle contacts the valve seat (20) or the sealing region (31) of the valve element (18) interacting with the valve seat (20) at points, in a longitudinal section plane of the fuel injector (1) accommodating a longitudinal center axis (L) of the valve element (18) of the control valve (19), at two points (P1, P2) spaced apart from one another and the center point (M) of the imaginary circle (26) is spaced apart less than 40%, advantageously less than 30%, preferably less than 20%, particularly preferably less than 20% of the axial guide length of the guide (24) from an axial center (25) of the guide (24).
摘要:
The invention relates to a fuel injector (1) having a high pressure region (32) which contains fuel that is under high pressure during operation, and a low pressure region (38) in which a lower pressure is present during operation than in the high pressure region (32). A sensor (12) is located in the low pressure region (38) and a transmission means (9) is arranged such that a force which is equal to the pressure of the fuel in the high pressure region (32) is exerted on the sensor (12) at least some of the time.
摘要:
The injector comprises a balanced metering servovalve to control a rod for the opening/closing of a nozzle. La servovalve has a valve body with a control chamber radially delimited by a tubular portion and fitted with an outlet passage that is opened/closed by an axially movable shutter. The servovalve is also integral with an axial stem, provided with a lateral surface, through which the outlet channel exits. The shutter is coupled to the stem in an axially sliding manner and, when it closes the outlet passage, it is subjected to substantially null axial fuel pressure. The outlet passage has a calibrated segment distanced from the shutter and close to a bottom wall of the control chamber. The calibrated segment is carried by an element fixed to the valve body in correspondence to an axial segment of the outlet passage.
摘要:
The invention relates to an injector, in particular, a common-rail injector for injection of fuel into a combustion chamber of an internal combustion engine. An injection valve element, adjustable between a closed position and an open position, is controllable by means of a control valve. The control valve has a control valve element, adjustable between a closed position and an open position by means of an actuator, which in the closed position is an at least almost pressure-equalized and has a sealing line which cooperates in a sealing manner with a control valve seat. The sealing line of the control valve element is lifted off the control valve seat in the open position and hence opens fuel flow from a high pressure region to a low pressure region of the injector. According to the invention, the control valve element has a support region extending over the sealing line in a radial direction to the high pressure region.
摘要:
The invention relates to a fuel injection valve for internal combustion engines, having a valve body, in which a pressure chamber is configured. A valve needle is disposed in the pressure chamber in a longitudinally displaceable manner. The valve body has a valve seat which interacts with a sealing surface configured on the valve needle. The valve seat delimits the pressure chamber, thus enabling or interrupting a fuel flow to at least one injection opening by the interaction of the valve needle with the valve seat. To this end, the fuel flow to the injection openings occurs between the valve needle and the wall of the pressure chamber, through a sharp-edged gap throttle which is formed between the valve needle and the wall of the pressure chamber.
摘要:
The invention relates to a fuel injector (1) for injecting fuel into a combustion chamber of an internal combustion engine, said injector comprising a nozzle needle (4) which moves back and forth in an injector body (2) and/or in a nozzle body (3) in order to release and/or to close at least one injection opening (5) in the nozzle body (3). The movement of the nozzle needle (4) can be controlled by a control valve which co-operates with a control chamber (6). The control valve comprises a valve needle (7) which is guided back and forth and can be moved in relation to a sealing seat (8) in order to ventilate the control chamber (6) in a fuel return (8) when the valve needle (7) is lifted from the sealing seat (8). The valve needle (7) has a differential surface which enables the needle to be subjected to a fuel pressure and held in the direction of the sealing seat (8).