The invention relates to an injection valve for internal combustion engine fuel injection systems. The valve is designed to inject fuel into the intake manifold. The valve comprises a valve housing containing a core, with which an armature cooperates. A nozzle body with a valve seat is connected to the valve housing. A sealing seat of a valve needle guided in the nozzle body cooperates with the valve seat. The valve needle is guided by first and second guide parts in a guide bore of the nozzle body and the second guide part, which is adjacent to the sealing seat in the upstream direction, is provided with metering bores. These metering bores are inclined such that they produce a spinning effect when the valve is open, thereby providing for good preparation of the fuel. According to the invention, each metering bore discharges immediately proximate to and directly upstream of, the sealing seat.
A fuel injection valve with a valve body in which a valve needle that has a longitudinal axis can slide in the longitudinal direction in a bore. The combustion chamber end of the bore is provided with a conical valve seat between the valve needle and the wall of the bore a pressure chamber is formed, which can be filled with fuel and extends to the valve seat. The valve needle has a valve sealing surface that cooperates with the valve seat in order to control at least one injection opening leading from the valve seat and contains an annular groove that extends in a radial plane of the valve needle. The downstream edge of the annular groove is embodied as a sealing edge and is hydraulically connected to the pressure chamber on a continuous basis.
Each swirl passages of the needle guide and fuel swirl member of a fuel injector has a longer and wider entrance portion and a shorter and narrower exit portion to allow only the latter portion, not the former portion, to perform a metering function. Production of swirl passages is facilitated and more consistent metering results.
An electromagnetically actuatable injection valves which tear away the fuel stream emerging from at least one injection port and atomize it as finely as possible. One possibility is to force a high velocity component in the radial direction upon the fuel prior to its leaving the injection valve; this is achieved with swirl generators. The novel injection valve has a valve seat face, which in a swirl segment outside a sealing face, is provided with four swirl conduits, which discharge into an injection conduit and terminal port with a lateral offset relative to a longitudinal valve axis. The novel injection valve is especially suitable as an injection valve for fuel injection systems of mixture-compressing internal combustion engines with externally supplied ignition.
An improved fuel injector for an internal combustion engine with structure which produces a counterforce on the injector valve subsequent to valve closing to inhibit substantial rebound movement of the valve away form its seating surface as caused by the impact of valve closing accompanied by elastic deformation of a valve and its seating surface. The counterforce is generated by creation of a reduced fluid pressure between closely spaced and parallel surfaces, one on the movable valve and the other on the stationary valve guide.
An improved fuel injector for an internal combustion engine which produces highly accurate fuel delivery control by providing a precise closing of the valve without secondary openings caused by rebound or bouncing of the valve from its seat surface after initial closing. Valve rebound is eliminated by a hydraulic cushion formed between parallel surfaces of the movable valve and its stationary guide whereby a thin boundary layer of liquid fuel caught between closely spaced surfaces is compressed just prior to engagement of the valve with its valve seat. This generates an opposing force to the force tending to close the valve.