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 and gas mixing structure for an engine is provided. This mixing structure includes a body configured to be positioned between a fuel injector and a cylinder of an engine. The body defines an interior volume that is configured to receive gas from outside the body and to receive one or more streams of fuel from the fuel injector in the interior volume. The body also defines one or more mixture conduits configured to conduct plumes of the fuel and gas, while mixing, from the interior volume to one or more exit ports and therethrough to the cylinder.

The purpose of the present invention is to provide a fuel injection valve that can achieve sufficient atomization even if the spray angle is narrow. The present invention is a fuel injection valve, in which fuel flowing in from a fuel passage section 5c is made to flow so as to diffuse from the center of a fuel diffusion chamber 6B toward the outer circumference and to flow into a nozzle hole 7, wherein: the nozzle hole 7 comprises a first nozzle hole 7b, and a second nozzle hole 7d and a third nozzle hole 7a that neighbor the first nozzle hole 7b and are separated therefrom in the circumferential direction of the fuel diffusion chamber 6B; and, if the distance L4 between the center of the entry-side opening of the first nozzle hole 7b and the center of the entry-side opening of the second nozzle hole 7d is greater than the adistance L1 between the center of the entry-side opening of the first nozzle hole 7b and the center of the entry-side opening of the third nozzle hole 7a, the exit-side opening of the first nozzle hole 7b is disposed on the inside of an arrangement circle 101 and on the second nozzle hole 7d side of a line segment 107.

In a fuel injector 10, a first injection hole 155a and a second injection hole 155b having reference inside diameters Dn1, Dn2 different from each other are formed as a plurality of injection holes 155. In such a configuration, an L/D value obtained by dividing the flow channel length Ln1 of the first injection hole 155a by the reference inside diameter Dn1 of the first injection hole 155a agrees to an L/D value obtained by dividing the flow channel length Ln2 of the second injection hole 155b by the reference inside diameter Dn2 of the second injection hole 155b.

An improved fuel injection device for internal combustion engines comprising a slidable (pilot) valve instead of a needle valve principle. The valve does not comprise a seat, so, even in the case of a spring-loaded embodiment of the valve there is no risk of hammering of the valve on a seat with the pertaining generation of noise.

The improved fuel injector allows a larger nozzle diameter and, therefore, a larger number of nozzle holes, if required or deemed useful.

For rotating embodiments of the fuel injector, the valve or at least its spring, in the case of a spring-loaded embodiment of the valve, can be located in the static section of the rotating fuel injector, thus eliminating the balancing problem of prior art rotating fuel injectors which comprise a spring in the rotating section.

The present invention is a compression-ignition direct-injection internal-combustion engine comprising at least a cylinder, a cylinder head carrying fuel injection, a piston sliding in the cylinder, a combustion chamber limited on one side by upper face of the piston comprising a projection extending in the direction of the cylinder head and in the center of a concave bowl (46) with at least two mixing zones. The fuel injection projects fuel in at least two fuel jet sheets with different sheet angles, with a lower sheet having a jet axis C1 for one zone and an upper sheet having a jet axis for the other zone. The injection feeds fuel into the combustion chamber with a different flow rate for each sheet for dedicated targeting in the mixing zones of the combustion chamber.

An injector includes a nozzle body extending along a longitudinal axis and at least one spray hole extending through a portion of the nozzle body to output a fluid from the injector. The spray hole includes at least one groove. The groove is configured to facilitate efficient mixing of the fluid with air or other surrounding materials for enhanced performance of the injector and/or other components associated with the injector.

A fuel injector for a compression ignited engine comprises an injector nozzle with a nozzle body having at least one spray hole with a hole entry from a sack on the inside of the nozzle body and a hole exit on the outside of the nozzle body. The hole entry of the spray hole has a cross-section being elliptical and larger than the cross-section of the hole exit of the spray hole. The cross-sections of the hole entry and the hole exit of the spray hole are concentric as seen in the direction of a centre axis of the spray hole intersecting said cross-section.

An object of the present invention is to provide a fuel injection device in which fuel sprays hardly adhere to an intake valve, a wall surface in an engine cylinder, or a piston.

In a fuel injection device including a valve body 114 and a seat surface 601 to perform injection and sealing of fuel cooperatively and a plurality of injection holes 501 and 502 of which inlet opening surfaces are formed on the seat surface 601, a first injection hole 501 and a second injection hole 501 and 502 arranged closest to the first injection hole 501, which configure the plurality of injection holes 501 and 502, are configured such that the first injection hole 501 is larger than the second injection hole 502 in an injection hole angle to be an angle formed by a normal direction 601a of the seat surface 601 and a center axis 119a of the injection hole (1>2) and the second injection hole 502 is larger than the first injection hole 501 in an area of a cross-section perpendicular to the center axis 119a of the injection hole (injection hole diameter Da2>injection hole diameter Da1).

A gas injector for injecting a gaseous fuel directly into a combustion chamber of an internal combustion engine includes a valve-closing element for releasing and sealing a through opening at a sealing seat; a shielding element, which is situated at an end of the valve-closing element on a side of the combustion chamber and which shields the valve-closing element and the sealing seat with respect to the combustion chamber; and a cooling ring having a first contact area designed for direct contact with the shielding element and a second contact area designed for direct contact with a component of the internal combustion engine, in particular with a cylinder head.