Electromagnetic fuel injection valve with swirl means

Claim 1

An electromagnetic fuel injection valve, comprising: a tubular housing including inlet means and outlet means axially aligned at opposite ends of said housing; an electromagnetic actuator situated axially within said housing including a spool-shaped bobbin, an electromagnetic coil wound upon said bobbin, and a frame assembly comprising inner and outer frame pieces arranged to form a pole piece at the outlet end of said actuator; a washer-shaped electromagnetic armature situated axially between said pole piece and said outlet and arranged to be axially attracted to said pole piece, said pole piece and said armature being of such configuration so that there is substantially no magnetic force of attraction between them other than at right angles to the face of said armature; a valve seat downstream from said electromagnetic armature; a spherically-shaped valve member attached to said armature and arranged to cooperate with said valve seat to control flow of fuel therethrough; spring biasing means acting to urge said spherical valve member toward the closed position; an orifice downstream of said valve seat; and swirl means located between said valve seat and said orifice for imparting a radial velocity component to fuel flowing through said valve seat, said swirl means comprising a plug member occupying the cavity between said valve seat and said orifice, said plug member separting the cavity between said valve seat and said orifice into an entrance cavity at the outlet of the valve seat and an exit cavity adjacent to said outlet orifice, said exit cavity being defined by a conical extension of said plug member and a corresponding conically shaped wall on said housing, passageways in said plug member inclined at angle with respect to the valve axis for imparting a radial velocity to fuel flowing from the valve.