摘要:
A fuel injector has an injector body extending along a given axis; a tubular valve body housed inside a hole in the injector body and coaxial with the injector body; and an annular chamber defined by the injector body and the valve body. The method of producing the injector includes connecting the valve body to the injector body, and fixing the valve body in a given position along the axis with respect to the injector body by means of a driving operation to interference fit the valve body inside the hole in the injector body.
摘要:
A control servo valve is housed inside the casing of an internal combustion engine fuel injector, and has an actuator, a control chamber communicating with a fuel inlet and with a fuel outlet passage, and a shutter movable along an axis by the actuator between a closed position and an open position to close and open the outlet passage respectively; the servo valve also has a fixed axial rod interposed between the actuator and the control chamber; the outlet passage comes out through an outer lateral surface of the axial rod; and the shutter is defined by a sleeve which slides axially on the outer lateral surface, and, in the closed position, closes the outlet passage so as to be subjected to a zero axial resultant force by the pressure of the fuel.
摘要:
A control servo valve (8) is housed inside the casing (2) of an internal combustion engine fuel injector (1), and has a piezoelectric actuator (40), and a control chamber (13) having a fuel outlet passage (21); the outlet passage (21) comes out inside an annular chamber (34) defined by a fixed tubular portion (25) and by a shutter (32), which engages the tubular portion (25) in substantially fluidtight manner and is slid axially by the piezoelectric actuator (40) from a closed position, in which it closes the annular chamber (34) and is subjected to a zero axial resultant force by the fuel pressure, to an open position, in which the outlet passage (21) communicates with a discharge conduit.
摘要:
The fuel injector comprises a hollow casing, fixed on which is a nozzle having a nebulizer for the fuel under pressure, a needle axially mobile for opening and closing the nebulizer by means of a first end thereof, and a control rod, substantially coaxial with the needle and in direct engagement therewith. The needle is normally pushed into a closing position of the nozzle by the fuel under pressure acting on the rod, aided by a compression spring, which acts on the needle through a sleeve that is in axial engagement with a portion of the rod. The sleeve further comprises a surface designed to engage at the front and directly one end of the needle. The spring engages another surface of the sleeve so as to transmit its action directly onto the needle.
摘要:
A fuel injector (1) for an internal-combustion engine has a shell (2) provided with two opposite terminal portions; the first terminal portion (4) has an inlet (7) for supply of the fuel and is generally designed to extend outside the engine, whilst the second terminal portion (5) has a nozzle (9) communicating with said inlet (7), is designed to be housed in the engine and has, in the radial direction, dimensions smaller than those of the first portion (4); the injector (1) further has an actuator (16) and a servo valve (15) housed in the first terminal portion (4); the servo valve (15) is provided with an open/close element (32), which can slide axially, under the action of the actuator (16) and substantially in a fluid-tight way, in a seat (27) and is subjected to an axial resultant of pressure of the fuel that is substantially zero; the fuel inlet (7) is made laterally in an intermediate axial position between the actuator (16) and the nozzle (9).
摘要:
A fuel injector has an injector body extending along a given axis; a tubular valve body housed inside a hole in the injector body and coaxial with the injector body; and an annular chamber defined by the injector body and the valve body. The method of producing the injector includes connecting the valve body to the injector body, and fixing the valve body in a given position along the axis with respect to the injector body by means of a driving operation to interference fit the valve body inside the hole in the injector body.
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:
The fuel injector comprises a hollow casing, fixed on which is a nozzle having a nebulizer for the fuel under pressure, a needle axially mobile for opening and closing the nebulizer by means of a first end thereof, and a control rod, substantially coaxial with the needle and in direct engagement therewith. The needle is normally pushed into a closing position of the nozzle by the fuel under pressure acting on the rod, aided by a compression spring, which acts on the needle through a sleeve that is in axial engagement with a portion of the rod. The sleeve further comprises a surface designed to engage at the front and directly one end of the needle. The spring engages another surface of the sleeve so as to transmit its action directly onto the needle.
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:
The injector has a hollow body supporting an ordinary injection nozzle and a metering valve for metering the fuel to be injected; and a support defined by a sleeve and by an end wall. The sleeve houses an electromagnet controlling the metering valve, and is fitted to the hollow body. For which purpose, there is provided a leaf spring having a ring-shaped portion engaging the end wall of the support; and a number of elastic blades, each terminating with a hook-shaped appendix which engages a corresponding retaining element on the hollow body.