Abstract: 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.

Abstract: 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).

Abstract: The pump (7) is provided with a body (16) having a compartment (17), and with at least one pumping element (13) that moves in a cylinder (12) in communication with the compartment (17), to raise the pressure of the fuel. The pump (7) comprises fluid-supply means (14, 22) for delivering the fuel to the pumping element (13), and an inlet mouth (26) made in the body (16) and supplied with the fuel coming directly from an external source (2). The inlet mouth (26) is fluidically connected to the compartment (17) to supply it with the fuel in order to lubricate and/or cool the pump (7) itself. Set between the inlet mouth (26) and the compartment (17) are: a non-return valve (33) to prevent in any case the pumping elements (13) from sucking the fuel from the compartment (17) of the body (16); and a flow regulator (29?), which allows an amount of fuel to pass such as to enable proper lubrication and cooling of the compartment (17) and of the parts present in the compartment (17).

Abstract: 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.

Abstract: The injection system has a high-pressure pump (7) having at least one pumping element (18) operated reciprocatingly to perform an intake stroke and a delivery stroke. Each pumping element (18) has a corresponding intake valve (25) communicating with an intake conduit (10) supplied by a low-pressure pump (9). The intake conduit (10) is fitted with an on-off solenoid valve (27) controlled by a control unit (16) asynchronously with respect to the intake of each pumping element (18). And the control unit (16) may control the on-off solenoid valve (27) by means of frequency-modulated and/or duty-cycle-modulated control signals (A, C).

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: 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: 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 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 (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).

Abstract: A system for controlling filling a motor-vehicle tank with LPG, comprises: a normally-closed valve, which can be driven in opening by excitation of a solenoid; sensor means, pre-arranged to emit an electrical signal indicating that a pre-set maximum level of LPG in the tank has been reached; and a control member, which can be operated manually for generating an electrical signal indicating the intention to proceed with filling the tank. The system further comprises a control circuit, which is independent of the circuit on board the motor vehicle and which is active even when the vehicle engine is turned off and is pre-arranged for exciting the solenoid of the valve in order to control opening thereof when it receives the aforesaid signal indicating activation of the mode of filling of the tank, and for de-exciting the aforesaid solenoid in order to control closing of the valve when the signal indicating that the pre-set maximum level of LPG in the tank has been reached is received.

Abstract: A safety valve for pressurized tanks, particularly for tanks for containing methane or LPG for motor vehicles, comprises an open/close element that is kept by elastic means in a closing position, in which it does not enable communication of the internal cavity of the tank with the external atmosphere. When a pre-set maximum value of the pressure inside the tank is exceeded, sufficient for overcoming the load of said elastic means, the open/close element is displaced from its closing position and enables discharge of the gas contained in the tank into the external atmosphere. The elastic means are arranged in series with a fuse element, which is set between the open/close element and the valve body. In this way, whenever the temperature -exceeds a pre-set maximum value, the fuse element melts, causing unloading of said elastic means, which consequently leaves the open/close element free to open.