1. Field of the Invention
This invention relates to a fuel injection valve and in particular, although not exclusively, to a fuel injection valve for an internal combustion engine, such valves may be actuated, for example, electro-mechanically, mechanically or hydraulically.
2. Description of the Related Art
One known electro-magnetic fuel injection valve has a reciprocal ball valve and fuel is supplied to the ball valve in the axial direction of reciprocation. Such a valve tends to provide a non-uniform distribution of fuel drops.
Another known electro-magnetic fuel injection valve has a structure wherein a fuel is swirled at an upstream side of an injection hole and such a valve is known to produce finer fuel drops but they are still unacceptably non-uniform. A known injection valve is disclosed in Japanese Patent Application Laid-Open No. 56-75955 (1981). In such a conventional injection valve, a swirl plate has a guide hole for receiving a ball and a swirl passage for introducing fuel to the guide hole in a substantially tangential direction.
In the above prior art injection valve, the spray from the injection guide hole spreads in a conical shape and produces large size drops and the drop distribution near the valve axial center is reduced. However, previously, no consideration has been given to such a problem.
The present invention seeks to provide a fuel injection valve having a uniform distribution of fuel spray and drop size.