An opening intersection point is between a nozzle hole axis and an inlet opening portion. A normal line of a suction wall surface at the opening intersection point intersects a nozzle hole inner wall or an imaginary inner wall which is an extension of the nozzle hole inner wall. A distance from an outlet opening portion to an inner wall intersection point, which is an intersection point between the normal line and the nozzle hole inner wall or the imaginary inner wall, is LA. An nozzle hole length between the inlet opening portion and the outlet opening portion of the nozzle hole inner wall on a side where the inner wall intersection point is formed is LB. The nozzle hole is provided such that LA/LB>?0.2.

In a fuel injection device including a body portion that forms an injection hole through which a fuel is injected, the body portion includes an inlet-channel-forming portion that is connected to an inflow port of the fuel in the injection hole and forms an inlet channel which is a fuel flow channel, and an outlet-channel-forming portion that is connected to the inlet channel and an outflow port of the fuel in the injection hole, and forms an outlet channel that is a fuel flow channel. A surface roughness of the outlet-channel-forming portion is larger than a surface roughness of the inlet-channel-forming portion.

A valve (or fuel injector), which provides that the valve-seat member exhibits high structural strength and fatigue strength under vibratory stresses, includes an excitable actuator for actuating a valve-closing member which, with a valve-seat face on the valve-seat member, forms a sealing seat, and injection openings which are downstream of the valve-seat face, the injection openings being in a center area of the valve-seat member projecting outwardly dome-like in the injection direction. The dome-like center area has a curved outer contour, the curvature in a radially inner section having a larger radius than the radius of the curvature in a radially outer section of the dome, which ends radially outside the mouth areas of all injection openings, in a recessed depression, that is followed radially outwardly by an axially projecting edge area of the valve-seat member. The fuel injector directly injects fuel into a combustion chamber of an engine.

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.

It is prevented that residual fuel left in the vicinity of an injection nozzle outlet is carbonized to cause adherence of the carbonized fuel as deposit and changing of a spray pattern or an injection flow rate. A fuel injection valve includes a seat portion on which a valve body is seated and a seat portion in which an injection hole for injecting fuel downstream from the seat portion is formed, in which a concave surface denting in a direction opposite to a fuel injecting direction is formed on an outer peripheral side away from the injection hole at an end face located downstream of the seat member, and the concave surface is formed such that a material surface in an outer peripheral region has a larger wettability for the fuel than in an inner peripheral region.

A first injection hole included by an injection nozzle is formed such that an angle that a first virtual line passing a first inner-wall-side center point away from a center axis by a predetermined first distance, forms with the center axis becomes a first injection angle, and an angle that first injection hole inner walls form becomes a first open angle. A second injection hole included by the injection nozzle is formed such that an angle that a second virtual line passing a second inner-wall-side center point away from the center axis by a predetermined second distance, forms with the center axis becomes a second injection angle that is smaller than the first injection angle, and an angle that second injection hole inner walls form becomes a second open angle that is larger than the first open angle.

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.

A method for manufacturing a member having a through hole includes a primary formation step, an intensity determination step, a laser modulation step, and a secondary formation step. The primary formation step includes radiating a laser beam to a workpiece member to form a pilot hole having a smaller inner diameter than the through hole while receiving light from the workpiece member at a light detection unit. The intensity determination step includes determining whether a light intensity is equal to or less than a predetermined threshold value. The laser modulation step includes modulating a spatial light phase of the laser beam the intensity of the light is equal to or less than the predetermined threshold value. The secondary formation step includes radiating the laser beam having the modulated spatial light phase to a peripheral part of the pilot hole to form the through hole.

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).

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.