A flow control system for a fuel injector of an internal combustion engine includes: an inlet channel, an outlet channel, a return channel for returning pressurized fuel to a low-pressure system having a lower pressure than the inlet channel, a fuel outlet chamber, a moveable nozzle control member in the fuel outlet chamber for selectively allowing the pressurized fuel to flow into the outlet channel, a biasing member biasing the nozzle control member towards a closed position, a moveable member defining, with the nozzle control member, a fuel control chamber configured to bias the nozzle control member towards its closed position, a moveable valve member for selectively opening and closing a flow passage and a fuel connection between the inlet channel and the fuel control chamber for pressurizing the fuel control chamber.

Device for controlling an injector, including a passage space which can be closed off on one of its two sides by an armature element in order to thereby optionally separate a fluid high-pressure region from a fluid low-pressure region of the injector, a control space for applying a variable pressure to an injector component, preferably an injector needle, a valve which is arranged between another of the two sides of the passage space and the control space, a first connection which connects the high-pressure region of the injector to the passage space, and a second connection which connects the passage space to the control space, wherein the valve is configured to establish a direct connection between the high-pressure region and the control space if the pressure level in the passage space is equal to or higher than a predetermined value.

A flow control system for a fuel injector of an internal combustion engine includes: an inlet channel, an outlet channel, a return channel for returning pressurized fuel to a low-pressure system having a lower pressure than the inlet channel, a fuel outlet chamber, a moveable nozzle control member in the fuel outlet chamber for selectively allowing the pressurized fuel to flow into the outlet channel, a biasing member biasing the nozzle control member towards a closed position, a moveable member defining, with the nozzle control member, a fuel control chamber configured to bias the nozzle control member towards its closed position, a moveable valve member for selectively opening and closing a flow passage and a fuel connection between the inlet channel and the fuel control chamber for pressurizing the fuel control chamber.

An electrically actuated control valve has three mouths and three operating positions, in which the three mouths includes a first mouth for inlet of a working fluid, and a second mouth and a third mouth for outlet of the working fluid. The three operating positions include a first operating position in which a passage of fluid from the first mouth to the second mouth and the third mouth is enabled, a second operating position in which a passage of fluid from the first mouth to only one of said second and third mouths is enabled, and a third operating position in which the passage of fluid from the first to the second mouth and the third mouth is disabled. The control valve includes an electric or electromagnetic actuator for controlling the passage of fluid from the first mouth to the second and third mouths providing the aforesaid three operating positions.

A fuel injector includes a control valve assembly arranged between an actuator assembly and a nozzle assembly. A 3-way valve controls flow for filling or draining a control chamber through a first throttle and through a second throttle for enabling or preventing fuel injection. The second throttle is a through orifice provided in a plate arranged in the control chamber.

A fuel injection valve includes a needle valve that controls communication between a high pressure chamber and an injection hole, a follower valve provided inside a control chamber controlled by fuel pressure inside an intermediate chamber, and an open-close valve that controls communication between a first passage and a low pressure passage and communication between a second passage and the low pressure passage. The fuel injection valve is configured to control the gradient of the fuel injection rate from the injection hole with an improved configuration.

The invention relates to a fuel injector (1) for operating with combustible gas. The fuel injector has a plurality of combustible-gas nozzle valve elements (9), and the stroke of each of the combustible-gas nozzle valve elements can be controlled by means of a paired hydraulic piston control assembly (55) of the fuel injector, wherein each piston control assembly is formed by two control chambers (59, 61) and a piston section (63) on the combustible-gas nozzle valve element paired with the piston control assembly, said piston section separating the control chambers in such a way that their volumes can be varied, and the fuel injector is designed to control the stroke of the combustible-gas nozzle valve elements in tandem using a 3/2-way valve (67), by means of which the hydraulic pressure in one of the two control chambers of the piston control assemblies is controlled.

The invention relates to a fuel injector (1) for operating with combustible gas. The fuel injector has a plurality of combustible-gas nozzle valve elements (9), and the stroke of each of the combustible-gas nozzle valve elements can be controlled by means of a paired hydraulic piston control assembly (55) of the fuel injector, wherein each piston control assembly is formed by two control chambers (59, 61) and a piston section (63) on the combustible-gas nozzle valve element paired with the piston control assembly, said piston section separating the control chambers in such a way that their volumes can be varied, and the fuel injector is designed to control the stroke of the combustible-gas nozzle valve elements in tandem using a 3/2-way valve (67), by means of which the hydraulic pressure in one of the two control chambers of the piston control assemblies is controlled.

A fuel injection method includes applying a first method current to close a spill valve according to a first method, applying a control valve current to open a control valve, and discontinuing the application of the control valve current to thereby cause the control valve to close. The method also includes applying a second method current to maintain the spill valve closed according to a second method and detecting a timing of a closing of the control valve while applying the second method current according to the second method, the second method being different than the first method.

An injector is provided, comprising an injector body comprising an inlet passage configured to receive fluid, at least one injection outlet configured to deliver fluid, and a central bore, a needle valve disposed for reciprocal movement within the central bore between a closed position and an opened position; and an actuator configured to move the needle valve between the closed position wherein a first portion of a surface of the valve tip engages a first portion of a surface of the injector body to form a first seal that inhibits flow through the at least one injection outlet, and the opened position wherein a second portion of the surface of the valve tip engages a second portion of the surface of the injector body to form a second seal that inhibits flow through the drain outlet.