Abstract: In order to reduce the size of a tubular rail for a high-pressure fluid, the rail is obtained from a hollow body with an external diameter and an internal diameter, and has two terminal portions, each provided with an external milling to favour gripping thereof. The millings have an external diameter such as to ensure, together with a cylindrical portion of a coaxial element, a radial strength at least equal to that of the hollow body. Made between the hollow body and each cylindrical portion is a front connection. For this purpose, the cylindrical portion has a plane front surface, whilst each terminal portion has an internal milling with an internal diameter greater than the internal diameter of the hollow body so as to house the cylindrical portion and so as to form an annular shoulder. A washer of softer material is set between the annular shoulder and the front surface.

Abstract: 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).

Abstract: A fuel-injection system (1, 1?, 1?, 1??) for an internal-combustion engine (2), of the type provided with: a tank (3) for collection of the fuel; compressor system (4) for drawing in the fuel from the tank (3) and making it available at high pressure to an storage volume (7); at least one injector (8, 8?, 8??) hydraulically connected to the storage volume (7) for taking in the fuel at a high pressure from the storage volume (7) and injecting it into a respective combustion chamber (12) of the engine (2); a fluid line (17) connecting the storage volume to the tank; and pressure-regulator means (19) in the storage volume (7) set along the fluid line (17); the pressure-regulator systems (19) are set hydraulically downstream of the storage volume (7) so as to enable a continuous flow of fuel through the storage volume (7) itself.

Abstract: The high-pressure pump (7) comprises a number of pumping elements (18) actuated in reciprocating motion through corresponding suction and delivery strokes. Each pumping element (18) is provided with a corresponding intake valve (25) in communication with an intake pipe (10) supplied by a low-pressure pump (9). Set on the intake pipe (10) is an on-off solenoid valve (27) having a reduced flow rate substantially of the same order of magnitude as the maximum amount of fuel that can be injected by an injector (5). The solenoid valve (27) is controlled in a chopped way in synchronism with an intermediate part (32) of the suction stroke of each pumping element (18).

Abstract: The high-pressure pump (7) comprises a number of pumping elements (18) actuated in reciprocating motion through corresponding suction and delivery strokes. Each pumping element (18) is provided with a corresponding intake valve (25), in communication with an intake pipe (10), supplied by a low-pressure pump (9). Arranged on the intake pipe (10) is a shut-off valve (27) controlled in a choppered way in synchronism with an initial part (32; 32?) of the suction stroke of each pumping element (18).

Abstract: 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).

Abstract: 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.

Abstract: A fuel-injection system in an internal-combustion engine is provided with an electroinjector (1) comprising an injection nozzle (5), and a needle (7) mobile along an opening stroke and a closing stroke for opening/closing the nozzle (5) under the control of an electroactuator device (8). The opening stroke of the needle (7) is controlled by a rod (14) pushed by the pressure of the fuel in a control chamber (15), in such a way as to keep the needle (7) normally in the position for closing the nozzle (5). The control chamber (15) is equipped with an inlet duct (18) having a pre-set diameter (D4) and with an outlet passage (24) having a diameter (D5) and controlled by a control valve (16).

Abstract: The injection system has a pump for supplying high-pressure fuel to a storage volume for supplying a number of injectors. The pump has at least one reciprocating pumping element performing a compression stroke synchronously with each fuel injection. The injection system has at least one control device for controlling the amount of fuel supplied by the pump to the storage volume, and which is controlled by a chopper control unit to modulate the fuel volume introduced into the compression chamber during the intake stroke (Ps-Pi). The delivery start instant of the pumping element during the compression stroke being unequivocally defined by the fuel volume introduced.

Abstract: A control servo valve (8) is housed inside the casing of an internal combustion engine fuel injector (1), and has an actuator (9), a control chamber (13) communicating with a fuel inlet (5) and with a fuel outlet passage (22), and a shutter (35) movable along an axis (3) by the actuator (9) between a closed position and an open position to close and open the outlet passage (22) respectively; the servo valve (8) also has a fixed axial rod (29) interposed between the actuator (9) and the control chamber (13); the outlet passage (22) comes out through an outer lateral surface (30) of the axial rod (29); and the shutter (35) is defined by a sleeve which slides axially on the outer lateral surface (30), and, in the closed position, closes the outlet passage (22) so as to be subjected to a zero axial resultant force by the pressure of the fuel.

Abstract: The invention describes an injector device specifically designed for the injection of an alternative fuel such as LPG, methane, hydrogen or others, in an internal combustion engine. In the injector device, the shutter ensuring sealing in closing condition is separated with respect to the metering means with gauged hole, which perform the function of metering fuel during injection, and it is arranged downstream from said metering means. The shutter is controlled by a solenoid, which is again arranged on the downstream side with respect to said metering means.

Abstract: The injection system (1) includes a pump (7) for supplying high-pressure fuel to a storage volume, defined for example by a common rail (6), for supplying a number of injectors (5). The pump (7) has at least one reciprocating pumping member (18) with a sinusoidal compression stroke (24). The injection system (1) includes at least one bypass solenoid valve (14) controlled by a control unit (16) having a chopper unit (28) for producing multiple deliveries (29, 31) at each compression stroke (24), so that the pressure in the common rail (6) is substantially level. Each pumping member (18) may be associated with a corresponding bypass solenoid valve (14).

Abstract: A method is provided for controlling fuel injection in an internal-combustion engine provided with an electroinjector, including an electroactuator, an injection nozzle, and a pin, which is movable along an opening stroke and a closing stroke for opening/closing the nozzle under the control of the electroactuator and according to the supply pressure of the fuel into the electroinjector. The method supplies to the electroactuator a first electrical command and at least a second electrical command, which are sufficiently close to one another as to displace the pin with a profile of motion without any discontinuity in time, and such as to cause the pin to perform a first opening displacement and, respectively, a second opening displacement.

Abstract: In a gas-supply system for internal-combustion engines, a pressure-reducing valve is arranged between the reservoir of the gas and a distribution manifold or rail that feeds the gas to a series of electromagnetically controlled injectors associated to the various cylinders of the engine. The pressure-reducing valve has an internal chamber for collection of any leakage of gas which is connected to the intake manifold of the internal-combustion engine so as to enable the leaked gas to be discharged in the engine. A solenoid shutoff valve is arranged in the connection to the intake manifold and is opened automatically upon ignition of the engine.

Abstract: In a gas-supply system for internal-combustion engines, a pressure-reducing valve is set between the reservoir of the gas and a distribution manifold or rail that feeds the gas to a series of electromagnetically controlled injectors associated to the various cylinders of the engine. The pressure-reducing valve has a piston member that faces a chamber set downstream of a restricted passage defined inside the body of the valve in communication between the inlet connector and the outlet connector. The piston member is pushed by thrust means towards a position in which it causes opening of an open/close element (valve head) that controls the communication between said restricted passage and the inlet connector. The piston member is preferably provided with a single seal gasket that prevents leakage of gas towards the outside through the sliding coupling of the piston member within the respective guide bushing.

Abstract: A fuel tank for motor vehicles, for example an LPG fuel tank, contains inside it at least one electrical component and has a wall or a plate bearing at least one connector for connection of the electrical component with an electrical line external to the tank. The electrical connector has a body made of synthetic material or of elastomer material directly moulded on one or more conductor pins so as to guarantee hermetic sealing of the tank even in the presence of a pressure jump between the internal cavity of the tank and the external environment. In the case where the body of the connector is made of synthetic material, it bears seats for seal rings made of elastomer material. In the case where it is made of elastomer material, it guarantees directly the function of tightness. In either case, there are provided means for exerting an axial compressive force on the part that performs the tightness function.

Abstract: In a gas-supply system for internal-combustion engines, a pressure-reducing valve is set between the reservoir of the gas and a distribution manifold or rail that feeds the gas to a series of electromagnetically controlled injectors associated to the various cylinders of the engine. The reduced pressure supplied by the pressure-reducing valve is further reduced via a pressure-regulating solenoid valve, to an extent that depends upon the supply current of its solenoid. The electrical supply to the solenoid of said solenoid valve is controlled by an electronic control unit according to the signal issued by a sensor of the pressure in the rail and according to stored maps, which supply the optimal pressure value for each operating condition of the engine.

Abstract: In a gas-supply system for internal-combustion engines, a pressure-reducing valve is set between the reservoir of the gas and a distribution manifold or rail that feeds the gas to a series of electromagnetically controlled injectors associated to the various cylinders of the engine. The pressure-reducing valve brings about a pressure drop which depends upon a pilot-pressure signal that is sent thereto by a pilot solenoid valve. The electrical supply to the solenoid of said pilot solenoid valve is controlled by an electronic control unit according to the signal issued by a sensor of the pressure in the rail for the purpose of regulating the pressure in the rail at a desired level, according to the operating conditions of the engine.

Abstract: The injection system (1) includes a storage volume (6) of pressurized fuel supplied by a high-pressure pump (7) along a delivery pipe (8); and a control unit (16) for defining the required fuel pressure of the storage volume (6) as a function of the operating conditions of the engine (2). The regulating device includes a bypass solenoid valve (14); and a pair of non-return valves (32, 33) connected antiparallel and located between the bypass valve (14) and the storage volume (6). One of the non-return valves (32, 33) permits fuel drainage from the storage volume (6) to the bypass valve (14) when the control unit (16) defines a predetermined reduction (?p) in the fuel pressure of the storage volume (6).

Abstract: 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.