A fuel injection device that injects a liquefied gas fuel from an injection port to a combustion chamber of the internal combustion engine includes a passage forming member configured to define a fuel passage through which the liquefied gas fuel flows to the injection port, a temperature regulating unit configured to adjust a temperature of the liquefied gas fuel flowing through the fuel passage according to an operation state of the internal combustion engine, and a pressure regulating unit configured to adjust a pressure of the liquefied gas fuel flowing through the fuel passage according to the operation state of the internal combustion engine.

An injector, comprising, an injector body comprising, an inner wall that defines an injector cavity for fluid, at least one inlet channel into the injector cavity, and at least one outlet channel from the injector cavity, a plunger that defines at least one passageway between the injector cavity and the at least one outlet channel, the plunger being movable longitudinally in the injector cavity between at least: a first open arrangement in which the at least one passageway is positioned to direct fluid into the at least one outlet channel at a first position, and a second open arrangement in which the at least one passageway is positioned to direct fluid into the at least one outlet channel at a second position different from the first position.

An internal combustion engine includes a fuel injection nozzle provided with a nozzle hole for injecting fuel, the nozzle hole exposed from a cylinder head of the internal combustion engine to a combustion chamber, and a hollow duct, an inlet and an outlet of which are exposed to the combustion chamber. The duct is provided in a manner allowing fuel spray injected from the nozzle hole of the fuel injection nozzle to pass through from the inlet to the outlet. The fuel injection nozzle and the duct are configured such that a part of fuel spray that is injected in pilot injection that is performed before main injection directly adheres to an inner wall surface of the duct.

An injection hole body has an injection hole to inject fuel for causing combustion in an internal combustion engine. A valve body is unseated from and seated on a seating surface of the injection hole body. The injection hole body and the valve body form a fuel passage therebetween to communicate with an inflow port of the injection hole. The fuel passage is opened and closed by unseating and seating of the valve body. A resilient member generates a resilient force to urge the valve body toward the seating surface. A seat angle is an angle between two straight lines appearing in a cross section of the seating surface, the cross section including a center axis of the valve body. The seat angle is 90 degrees or less.

Among all combinations of two injection holes, in a combination in which when the injection holes are offset such that their central axes are coincident with each other in inlet openings, an inter-injection hole angle formed by the central axes is minimized, the inter-injection hole angle between the two injection holes is represented as a min[deg], taper angles, which are formed by the respective contours of the injection hole inner walls in the cross sections along the virtual planes including the central axes of the two injection holes that allow the inter-injection hole angle to be minimized, are represented as a1 and a2[deg], and when fuel is injected from the injection holes, average pressure of the fuel in the fuel passage is represented as P[Mpa], and the injection holes are formed so as to satisfy a relationship: a mina1+a2+0.5P.sup.0.6.

A fuel injection valve according to the present invention has an expanded portion formed in a first injection-hole plate on an upstream side, thereby allowing positional misalignment between injection-hole portions. As a result, a radial dimension between an inner diameter-side circumferential edge of an upstream-side injection hole outlet portion and an inner diameter-side circumferential edge of a downstream-side injection hole inlet portion is not required. Thus, a plate thickness of a second injection-hole plate on a downstream side can be kept to minimum. As a result, weldability between an injection-hole plate body and a valve seat is improved.

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 internal combustion engine includes a fuel injection nozzle that is arranged at the center of an upper surface of a combustion chamber with an injection port thereof exposed in the combustion chamber, and a piston arranged in a cylinder. On a top surface of the piston, a flow guide passage is provided which extends from an inlet exposed on the side of a wall of a bore of the cylinder to an outlet exposed on the side of a center of the bore. The flow guide passage preferably includes a flow guide plate having a ring shape, and a strut that fixes the flow guide plate to the top surface of the piston in such a manner that a clearance extending from an outer edge to an inner edge of the flow guide plate is formed between the flow guide plate and the top surface of the piston.

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.

Provided is a structure capable of reducing dribbling of fuel generated when a valve body is closed. In order to achieve the above object, a fuel injection device includes: a valve body; and a seat member having a seat portion on which the valve body is seated and having a fuel injection hole formed on a downstream side of the seat portion. The seat member is formed such that a gap between the seat member and the opposing valve body in the whole region on the downstream side of the fuel injection hole is smaller than a diameter of the fuel injection hole.