A throttle portion is defined between an upper end of a sac chamber and a conical portion of a needle to have a throttle opening area S1. Half of an area surrounded by the throttle portion, the needle, an inner wall of the sac chamber, and a lower end extended line in a cross section of the sac chamber taken along a sac center line is an injection hole upstream area S2. A lift amount, when the throttle opening area S1 is equal to an area which is calculated by multiplying an injection hole area S3 by the number of the injection holes, is a predetermined lift amount L. A viscosity coefficient of fuel is . An index value Sa, which is calculated in accordance with an equation as below, is set to 0.5 or greater. $S_a=\frac{}{2}{}_{h=0}^{h=L}{\left(\frac{S_1}{S_2-S_1}\right)}^2\mathrm{dh}$

A fuel injector 100 includes a nozzle member 60 having a fuel passage 60a leading to an injection port 60b; a valve main body 51 adapted to reciprocate for opening and closing the fuel passage 60a; an elastic portion 56 elastically deformable in closing the fuel passage 60a by movement of the valve main body 51 in a closing direction, the elastic member being attached to one of the nozzle member 60 and the valve main body 51 and adapted to be abutted against the other of the nozzle member 60 and the valve main body 51 to close the fuel passage 60a by moving the valve main body 51 in the closing direction; and a stopper 70 adapted to restrict movement of the valve main body 51 in the closing direction by being abutted against the valve main body 51, the stopper 70 being formed of material different from the nozzle member 60.

Methods and systems are provided for moving an injector needle of a fuel injector assembly from a first position to a second position to provide a first fuel injection at the first position, and moving the needle from the second position to the third position to provide a second fuel injection at the third position, and moving the needle back to the first position via the second position, and providing a third fuel injection at the second position. In this way, three fuel injections may be performed during a single actuation cycle of the injector during a single combustion cycle.

A needle includes a first seal portion, which is formed at an end portion of the needle located on a side where an injection hole is placed, and a second seal portion, which is formed on a side of the first seal portion where a stationary core is placed. When a boundary between a first outer wall of the first seal portion and a second outer wall of the second seal portion is lifted away from or is seated against an inner wall, the injection hole is opened or closed. Thereby, a seat diameter of the boundary and the inner wall is stabilized, and a change in a fuel injection quantity caused by aging can be reduced. Furthermore, the first outer wall of the first seal portion is shaped into a form of a spherical surface.

A nozzle for a fuel injector the nozzle having a pivotably symmetrical nozzle member with a hollow space for introducing a nozzle needle, a nozzle tip at a longitudinal end of the nozzle member, at least one opening channel extending in a straight line for the discharge of fuel, and a nozzle needle arranged in the hollow space for selectively blocking an fuel inflow to the at least one opening channel. The nozzle is characterized in that the at least one opening channel has a center axis that is skewed with respect to the longitudinal axis of the nozzle member.

A control device of an engine including a cylinder, a piston, a cylinder head, and a combustion chamber is provided, which includes intake and exhaust ports, a swirl control valve provided in an intake passage connected to the intake port, a fuel injection valve attached to the cylinder head to be oriented into the center of the combustion chamber in a plan view thereof, and having first and second nozzle ports, and a control unit. The control unit includes a processor configured to execute a swirl opening controlling module to output the control signal to the swirl control valve to have a given opening at which a swirl ratio inside the combustion chamber becomes 2 or above, and a fuel injection timing controlling module to output the control signal to the fuel injector to inject fuel at a given timing at which the swirl ratio becomes 2 or above.

An injector tip for a fuel injector includes an exterior surface, and an interior surface defining a sac region therein. The injector tip is also configured to define at least one orifice radially extending from the interior surface to the exterior surface. The orifice is disposed in communication with the sac region located adjacent to the interior surface. Further, the injector tip also includes a mound that is defined on the interior surface such that the mound is integrally formed with the interior surface adjacent to the sac region. The mound is configured to extend along an axis of the sac region and terminate prior to a perimeter of the at least one orifice.

A metal valve body having a fuel injection port includes a nozzle plate accommodation part accommodating a nozzle plate of synthetic resin and aligning a center of the nozzle plate with a central axis of the valve body. A front end surface abutting against the nozzle plate is accommodated in the nozzle plate accommodation part. A swage projection fixes the nozzle plate to the front end side on which the fuel injection port is formed. The nozzle plate is swage-fixed in the state in which a spring action part is elastically deformed on the front end side of the valve body by the swage projection, and a nozzle hole formation part is constantly pushed against the front end surface of the valve body by the elastic force of the spring action part.

A metal valve body having a fuel injection port includes a nozzle plate accommodation part accommodating a nozzle plate of synthetic resin and aligning a center of the nozzle plate with a central axis of the valve body. A front end surface abutting against the nozzle plate is accommodated in the nozzle plate accommodation part. A swage projection fixes the nozzle plate to the front end side on which the fuel injection port is formed. The nozzle plate is swage-fixed in the state in which a spring action part is elastically deformed on the front end side of the valve body by the swage projection, and a nozzle hole formation part is constantly pushed against the front end surface of the valve body by the elastic force of the spring action part.

The present invention directly affects two primary limitations of diesel fuel: poor vaporization and ease of auto-ignition. Superheated fuel is injected within a cone of steam. As a result, fuel is fully vaporized and steam controls ignition by momentarily isolating fuel from air. In order to achieve high vapor velocities, the present invention uses momentum of circulating fuel and water to propel them through the injector. Momentum is preserved by transfer valves that transfer moving liquids between through paths and injection paths. Momentum is further preserved by an injector design that minimizes turbulence that would absorb energy and reduce injected velocity. The fuel and water may be superheated before injection to convert to steam and vapor upon the release of pressure when injected into the combustion chamber. The injector may also be used to achieve high injection velocity for liquid fuel injection without heating.