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 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 nozzle plate to be attached to a fuel injection port of a fuel injection device has, in a nozzle plate main body, a nozzle hole through which fuel injected from the fuel injection port passes. A spray direction change element colliding with fuel spray injected from the nozzle hole and changing the travel direction of the fuel spray is integrally formed near an outlet of the nozzle hole of the nozzle plate main body. Accordingly, the travel direction of spray is determined by the spray direction change element according to the shape of the intake pipe, the position of an intake port, and the like.

In an injection hole set, primary and secondary injection holes are formed to satisfy the following relationship: t1+t20.87P0.52, where (deg) is an injection-hole-to-injection-hole angle, which is an angle formed between a primary central axis of the primary injection hole and a secondary central axis of the secondary injection hole; t1 (deg) is a primary taper angle, which is an angle formed between outlines of a primary injection hole inner wall of the primary injection hole in a cross section of the primary injection hole inner wall; t2 (deg) is a secondary taper angle, which is an angle formed between outlines of a secondary injection hole inner wall of the secondary injection hole in a cross section of the secondary injection hole inner wall; and P (MPa) is an average pressure of the fuel in a fuel passage at a time of injecting the fuel from the injection holes.

At least one of nozzle holes is provided as a non-circular nozzle hole where the ratio of the longest diameter to the shortest diameter of an outlet opening portion is greater than 1. A virtual non-circular cone and a virtual circular cone are defined for each of the non-circular nozzle hole and a circular nozzle hole where the ratio of the longest diameter to the shortest diameter of the outlet opening portion is 1. At least two adjacent nozzle holes are formed such that the virtual non-circular cone does not interfere with the virtual circular cone or the virtual non-circular cone.

When it is determined that the igniting environment is out of the desired range, the variable valve mechanism is controlled so that the swirl ratio is increased. When the swirl ratio becomes high, the discharge spark and the initial flame move largely in the flow direction of the swirl flow SW and approach the closest fuel spray. Therefore, the discharge spark and the initial flame are attracted to the closest fuel spray and the initial flame enlarges by involving the closest fuel spray (middle stage of FIG. 7). Further, the initial flame enlarges further by involving surrounded fuel spray (lower stage of FIG. 7).

An injection nozzle that for a first fuel in a first mode and in a second mode ignition fluid for a second fuel is introduced. The injection nozzle includes an injection nozzle body with first and second injection orifices and a displaceable injection nozzle needle in the injection nozzle body. The first injection orifices have smaller injection orifice cross-sections than the second injection orifices and are arranged at a defined distance. In a first displacement direction for closing the orifices the first injection orifices are located in front of the second injection orifices and seen in a second displacement direction of the injection nozzle needle for the opening or unblocking of the orifices, the first injection orifices are located behind the second injection orifices.

A throttle body fuel injection system including a throttle body with at least one air intake, a fuel injector coupled to the throttle body at a fuel port and an annular ring coupled to the cylindrical inner wall of the air intake. The annular ring includes a primary fuel discharge orifice adjacent to the fuel port and a plurality of secondary fuel discharge orifices arranged radially around the annular ring for spraying atomized fuel into the air intake.

An engine includes: a piston including a cavity; a cylinder head configured so as to form a combustion chamber having a pent roof shape; a fuel injection valve configured to inject fuel in a period from a second half of a compression stroke until a first half of an expansion stroke; and a spark plug arranged at a position corresponding to an upper side of the cavity. Injection openings which are arranged in a circumferential direction surrounding a longitudinal axis of the valve and through each of which the fuel is injected in a direction inclined relative to the longitudinal axis by a predetermined angle is formed such that when a height of a ceiling of the combustion chamber at a position corresponding to an edge end portion of the cavity in an injection direction of the injection opening is large, the injection angle of the injection opening is large.

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.