Injection pump regulator systems for internal combustion engines

Claim 1

Fuel injection pump comprising a piston (6) movable in a pressure chamber of a casing (1) of the pump, means for imparting reciprocating and rotary motion to said piston in order to effect a combined action of pumping and of distribution to associated cylinders of an internal combustion engine, electronic means (c) for controllably regulating the throughput of the pump and through an actuator (23), controls the displacement of a fuel delivery control element (22), information feedback means (30, 31) responsive to said control element in the form of an annular regulation valve (20) having at least a slot (28) on its inner diameter cooperating with a plurality of discharge bores (26) formed on the outer surface of said piston (6) and connected with said pump pressure chamber, said annular valve 20 being traversed by said piston (6) and being generally axially constrained with respect to said pump casing (1) but capable of angular movement by the said actuator (23) for placing said at least one slot (28) in fluid communication with at least one of said plurality of discharge bores (26) to share the pumping stroke of said piston (6) and thus to determine the length of the active stroke of the piston (6) during fuel delivery, said at least one slot (28) on the inner diameter of the annular valve (20) runs obliquely with respect to the axis of said valve (20) and emerges on at least one planar face of said valve (20) said control element (22) being formed by a helical gear in mesh with a worm gear, said helical gear being defined by said regulation annular valve (20) in the form of a partial toothing of its outer circular surface, said regulation annular valve (20) having a radial ledge (36) cooperating with an adjustment screw (35) for effecting the maximum angular displacement of said regulation annular valve (20) and, consequently, the maximum delivery of the injection pump.