Abstract: A valve assembly for a fuel pump and having: a one-way outlet closing valve, which only allows fuel to flow out; a one-way pressure relief valve, which only allows fuel to flow in; a connector, which has a housing on the inside; a valve disc, which engages the housing of the connector and has a plurality of through outlet holes and a through relief hole; an annular body which is arranged in the housing of the connector and has a central through hole; a spring, which is part of the pressure relief valve, is arranged in the central hole of the annular body and pushes a shutter of the pressure relief valve; and a connection element interposed between the shutter of the pressure relief valve and the spring. The central hole of the annular body has an annular protuberance which constitutes a limit stop that limits the travel of the connection element.

Abstract: A valve assembly for a fuel pump and having: a one-way outlet closing valve, which only allows fuel to flow out; a one-way pressure relief valve, which only allows fuel to flow in; a connector, which has a housing on the inside; and a valve disc, which engages the housing of the connector and has a plurality of through outlet holes and a through relief hole. A shutter of the outlet closing valve consists of a flexible sheet, which is fixed to the valve disc and has: a plurality of shutting portions arranged in the area of the outlet holes; a peripheral mounting portion with an annular shape; a plurality of outer connection portions, each connecting the peripheral mounting portion to a corresponding shutting portion; a central mounting portion; and a plurality of inner connection portions, each connecting the central mounting portion to a corresponding shutting portion.

Abstract: A method to control a fuel pump for a direct injection system provided with a common rail comprising the steps of calculating the objective fuel flow rate to be fed by the high pressure pump to the common rail instant by instant to have the desired pressure value inside the common rail; comparing the objective fuel flow rate with the maximum flow rate that can be delivered by the high pressure pump; and, based on the comparison between the objective fuel flow rate and the maximum flow rate that can be delivered by the high pressure pump, controlling the high pressure pump so as to alternate operating cycles of the high pressure pump with the maximum flow rate that can be delivered and idle operating cycles of the high pressure pump.

Abstract: A method to control a fuel pump for a direct injection system provided with a common rail comprising the steps of calculating the objective fuel flow rate to be fed by the high pressure pump to the common rail instant by instant to have the desired pressure value inside the common rail; comparing the objective fuel flow rate with the maximum flow rate that can be delivered by the high pressure pump; and, based on the comparison between the objective fuel flow rate and the maximum flow rate that can be delivered by the high pressure pump, controlling the high pressure pump so as to alternate operating cycles of the high pressure pump with the maximum flow rate that can be delivered and idle operating cycles of the high pressure pump.

Abstract: A fuel pump for a direct-injection system provided with a common rail comprises a pumping chamber defined in a main body. A piston is mounted in a sliding manner inside the pumping chamber to cyclically vary volume of the pumping chamber. A suction channel is connected to the pumping chamber and regulated by a suction valve. A delivery channel is connected to the pumping chamber and regulated by a delivery valve. A flow-rate-adjustment device is mechanically coupled to the suction valve to keep, when necessary, the suction valve substantially open during pumping of the piston and includes a control rod that is coupled to the suction valve and an electromagnetic actuator that acts on the control rod and has a one-way hydraulic brake that is integral to and substantially slows movement of the control rod.

Abstract: A fuel pump for a direct-injection system provided with a common rail comprises a pumping chamber defined in a main body. A piston is mounted in a sliding manner inside the pumping chamber to cyclically vary volume of the pumping chamber. A suction channel is connected to the pumping chamber and regulated by a suction valve. A delivery channel is connected to the pumping chamber and regulated by a delivery valve. A flow-rate-adjustment device is mechanically coupled to the suction valve to keep, when necessary, the suction valve substantially open during pumping of the piston and includes a control rod that is coupled to the suction valve and an electromagnetic actuator that acts on the control rod and has a one-way hydraulic brake that is integral to and substantially slows movement of the control rod.

Abstract: The invention concerns novel Salmonella enterica attenuated strains, characterized in that they are inactivated at the level of the znuABC operon through mutation in at least one of the znuA, znuB, znuC genes of such operon, for uses in medical or veterinary fields as vaccines.

Abstract: Described herein is an electronic-injection fuel-supply system for an internal-combustion engine having at least one injector and a fuel pump; the fuel pump is provided with: a variable-volume pumping chamber; a one-way intake valve; a one-way delivery valve; a mobile piston that integrates within it the intake valve and is coupled to the pumping chamber to vary cyclically the volume of the pumping chamber itself; and an actuator device that impresses a reciprocating motion on the piston and has an electromagnetic actuator for actuating the piston during an intake phase and a spring for actuating the piston during a delivery phase.

Abstract: A fuel pump for an internal-combustion engine; the fuel pump is provided with: a variable-volume chamber for containing fuel; an intake valve connected to the variable-volume chamber; a delivery valve connected to the variable-volume chamber; and a pumping device for varying the volume of the first variable-volume chamber. The intake valve has a disk provided with a plurality of through supply holes, and a deformable lamina, which is fixed to the disk in a position corresponding to a peripheral edge thereof and is provided with a series of flaps, each of which is coupled to a respective supply hole.

Abstract: The invention concerns novel Salmonella enterica attenuated strains, characterized in that they are inactivated at the level of the znuABC operon through mutation in at least one of the znuA, znuB, znuC genes of such operon, for uses in medical or veterinary fields as vaccines.

Abstract: A fuel injector equipped with an injection valve comprising a mobile plunger ending with a sealing head; a support body having a tubular shape and comprising a feed channel; and a sealing body, in which is defined a valve seat of the injection valve; the sealing head is of a frustoconical shape, is arranged externally relative to the guide element, is thrust by a spring against said guide element in a direction contrary to the direction of feed of the fuel; the valve seat has a frustoconical shape which is a negative reproduction of the frustoconical shape of the sealing head in order to impart an internally hollow conical shape to the injected fuel.

Abstract: Described herein is an electronic-injection fuel-supply system for an internal-combustion engine having at least one injector and a fuel pump; the fuel pump is provided with: a variable-volume pumping chamber; a one-way intake valve; a one-way delivery valve; a mobile piston that integrates within it the intake valve and is coupled to the pumping chamber to vary cyclically the volume of the pumping chamber itself; and an actuator device that impresses a reciprocating motion on the piston and has an electromagnetic actuator for actuating the piston during an intake phase and a spring for actuating the piston during a delivery phase.

Abstract: A fuel injector has an injection valve having a movable pin terminating with a shutter head; a tubular supporting body having a feed channel; and a sealing body, in which a valve seat of the injection valve is defined; the shutter head is truncated-cone-shaped, is located outside the sealing body, and, in a closed position, is pushed against the sealing body in the opposite direction to the fuel feed direction; the pin has a stop member, which is integral with the pin and comes to rest on a top surface of the sealing body, when the pin is in the open position opening the injection valve, so as to determine travel of the pin.

Abstract: A fuel injector has an injection valve having a movable pin terminating with a shutter head; a tubular supporting body having a feed channel; and a sealing body, in which a valve seat of the injection valve is defined; the shutter head is truncated-cone-shaped, is located outside the sealing body, and, in a closed position, is pushed against the sealing body in the opposite direction to the fuel feed direction; the pin has a stop member, which is integral with the pin and comes to rest on a top surface of the sealing body, when the pin is in the open position opening the injection valve, so as to determine travel of the pin.

Abstract: A fuel pump for an internal-combustion engine; the fuel pump is provided with: a variable-volume chamber for containing fuel; an intake valve connected to the variable-volume chamber; a delivery valve connected to the variable-volume chamber; and a pumping device for varying the volume of the first variable-volume chamber. The intake valve has a disk provided with a plurality of through supply holes, and a deformable lamina, which is fixed to the disk in a position corresponding to a peripheral edge thereof and is provided with a series of flaps, each of which is coupled to a respective supply hole.

Abstract: A fuel injector equipped with an injection valve comprising a mobile plunger ending with a sealing head; a support body having a tubular shape and comprising a feed channel; and a sealing body, in which is defined a valve seat of the injection valve; the sealing head is of a frustoconical shape, is arranged externally relative to the guide element, is thrust by a spring against said guide element in a direction contrary to the direction of feed of the fuel; the valve seat has a frustoconical shape which is a negative reproduction of the frustoconical shape of the sealing head in order to impart an internally hollow conical shape to the injected fuel.

Abstract: In a fuel pump for an internal combustion engine, a pumping device is adapted to vary the volume of a first chamber containing the fuel and is formed by a second chamber adapted to contain oil, a deformable diaphragm for the leak-tight separation of the chambers from one another, and by a piston mounted to slide within the second chamber and comprising an active end surface bounding this second chamber; the diaphragm being adapted to be deformed to vary the volume of the first chamber under the action of the thrust exerted by the oil contained in the second chamber following an alternating movement of the piston within this second chamber.

Abstract: Fuel injection system of the common rail type provided with a high-pressure pump, which supplies fuel to a common channel that in turn supplies a series of injectors, and with a control unit, which is capable of keeping the pressure of the fuel within the common channel, moment by moment, equal to a desired value that generally varies over time; the control unit is coupled to a device for regulating the flow rate of the high-pressure pump in order to control the flow rate of the high-pressure pump so as to supply the common channel, moment by moment, with the amount of fuel required in order to have the desired value for pressure inside said common channel.

Abstract: Fuel injection system of the common rail type provided with a high-pressure pump, which supplies fuel to a common channel that in turn supplies a series of injectors, and with a control unit, which is capable of keeping the pressure of the fuel within the common channel, moment by moment, equal to a desired value that generally varies over time; the control unit is coupled to a device for regulating the flow rate of the high-pressure pump in order to control the flow rate of the high-pressure pump so as to supply the common channel, moment by moment, with the amount of fuel required in order to have the desired value for pressure inside said common channel.