摘要:
The invention relates to a fuel injector, in particular a common rail injector, for injecting fuel into a combustion chamber of an internal combustion engine. The fuel injector has an injection valve element which is adjustable between a closing position and an opening position and which is switchable by means of a control valve. The control valve has a sleevelike control valve element that is adjustable along an adjustment axis and in its closing position rests sealingly on a control valve seat element. According to the invention, it is provided that the control valve seat element is disposed movably relative to the adjustment axis of the control valve element.
摘要:
An injector with an adjustable-metering servo valve is provided. The injector has a shutter actuated by an armature of an electromagnet. The armature is mobile for an opening stroke defined by a surface of the core of the electromagnet, which is fixed in the casing by a ring nut and a hollow support of the core. The hollow support has a first contact surface that acts on a flange of the core. Set between the surface and a shoulder of the casing is a shim. An annular projection, having a second contact surface, is set between the surface and a shoulder of the casing. The second contact surface is contained at least in part in the area corresponding to the first contact surface so that the stroke of the armature is adjusted by plastic deformation of the shim or of the surface of the core.
摘要:
A fuel-injection system (1, 1′, 1″) for an internal-combustion engine (2), of the type provided with compressor mechanism (4) for making available the fuel at a high pressure to an storage volume (7), and a plurality of injectors (8, 8″) fluidically connected to the storage volume (7) for taking in the fuel from the storage volume (7) and injecting it into respective combustion chambers (12) of the engine (2). The compressor mechanism (4) advantageously generates at least two distinct delivery lines (14), which are connected to respective distinct fractions (16) of the storage volume (7).
摘要:
The metering servo valve comprises a valve body, an open/close element, and an electromagnet, and is housed in a shell of the injector. The electromagnet actuates a mobile armature for a travel defined by an arrest element, carried by the electromagnet, which is housed in a casing, fixed in the shell by means of a threaded ring nut. Said ring nut is screwed with a pre-set tightening torque on a thread of the shell. The casing has a resting surface designed to engage a shoulder of the shell. The surface is carried by an area of the casing designed to undergo deformation as a function of the tightening torque of the ring nut so as to enable fine adjustment of the travel of the armature.
摘要:
An internal combustion engine fuel injector (1) has a rod (10) movable along an axis (3) to open/close a nozzle, and a servovalve (7) having a control chamber (23) with a discharge passage (26) which is opened/closed by a shutter (17) movable axially under the control of an electro-actuator (14); the servovalve (7) also has a fixed axial rod (33) having an outer lateral surface (34) through which the discharge passage (26) comes out; the shutter (17) is fitted to the axial rod (33) to slide axially in substantially fluidtight manner, and, when closing the discharge passage (26), is subjected to substantially zero resultant axial pressure by the fuel; and the control chamber (23) is bounded radially by a tubular portion (8) formed in one piece with said axial rod (33).
摘要:
A fuel-injection system (1, 1′, 1″, 1′″) for an internal-combustion engine (2), of the type provided with compressor mechanism (4) for making available the fuel at a high pressure to an storage volume (7), and a plurality of injectors (8, 8′, 8′″) fluidically connected to the storage volume (7) for taking in the fuel from the storage volume (7) and injecting it into respective combustion chambers (12) of the engine (2). The storage volume (7) is advantageously split into a plurality of distinct elementary storage volumes (9, 9′, 9a, 9b) fluidically connected to one another.
摘要:
A servo valve (7) for fuel control is provided with an actuator (14) and a valve body (8, 28), which is set in a fixed position and has a stem (33) that extends along a longitudinal axis (3) and defines an internal passage (26); said internal passage (26) has at least two radial channels (39), which give out into an outlet through an outer lateral surface (34) of the stem (33) and have respective first portions (43) of calibrated length and cross section; said first portions (42) are followed by respective second portions of larger diameter; the servo valve (7) is provided with an open/close element (17), which is coupled to the outer lateral surface (34) of the stem (33) substantially in a fluid-tight way and is axially movable under the action of the actuator (14) for opening/closing the internal passage (26) of the stem (33); in the closing position, the open/close element (17) is subject to a zero axial resultant force by the pressure of the fuel.
摘要:
An internal combustion engine fuel injector (1) has a rod (10) movable along an axis (3) to open/close a nozzle, and a servovalve (7) having a control chamber (23) with a discharge passage (26, 48) which is opened/closed by a shutter (17) movable axially under the control of an electro-actuator; the servovalve also has a fixed axial rod (33) having an outer lateral surface (34) through which the discharge passage (26, 48) comes out; the shutter (17) is fitted to the axial rod (33) to slide axially in substantially fluidtight manner, and, when closing the discharge passage (26, 48), is subjected to substantially zero resultant axial pressure by the fuel; and a calibrated portion (42, 52) of the discharge passage (26, 48) is formed close to the outlet of the discharge passage to produce swirl and/or cavitation in the fuel outflow near to the closing area between the shutter (17) and the axial rod (33).
摘要:
A three-way valve including a valve housing having a valve chamber and a high pressure fluid supply inlet, high pressure fluid outlet and drain communicating with the valve chamber is disclosed. A movable member is reciprocally received in the valve chamber so as to be reciprocated between first and second positions for selectively fluidically communicating the outlet with either the inlet or drain. A first valve seat is formed in the valve housing and concentrically disposed in the valve chamber for sealing communication between the outlet and drain and a second valve seat is concentrically disposed in a cavity formed in the movable member for sealing communication between the inlet and outlet. A floating pin is received in the movable valve member cavity at a one end of the movable valve member and cooperates with the second valve seat for selectively sealing fluidic communication between the inlet and the outlet. An actuating device is mounted on the valve housing adjacent an end of the movable valve member opposite the floating pin for advancing the movable valve member toward the first position when energized and for allowing the movable valve member to retract to the second position when de-energized.
摘要:
An injector, including: a moveable armature having a bore and upper and lower control surfaces; a lower housing including a bore and upper and lower stationary control surfaces; and a flow geometry defined along an exterior of the armature. The armature includes a transverse flow path fluidly coupled with the armature bore and the flow geometry. The lower housing includes a transverse flow path fluidly coupled with the lower housing bore. Upon moving the armature from a first position to a second position, a first flow path is formed between the flow geometry and the lower housing transverse flow geometry through a space between the lower stationary control surface and the lower armature control surface, and a second flow path is formed between the armature bore and the lower housing transverse flow geometry through a space between the upper stationary control surface and the armature upper control surface.