GB1347488A - Liquid fuel injection pumping apparatus for an 'internal combustion engine - Google Patents

Abstract

1347488 Regulating I C engine fuel supply C A V Ltd 29 June 1971 [10 July 1970] 33570/70 Heading F1B An accumulator 14, Fig.1, charged by a pump 15, e.g. operated by an engine-driven cam, supplies fuel to an injector 10 having a valve member 12 controlling fuel flow to an orifice 11 for directing fuel to an engine combustion space. The valve member 12 is biased closed by fluid under pressure, e.g. fuel from the accumulator 14, and fuel flow to the injector is controlled by a valve 18. The valve element 19 is lifted from its seat 20 to permit fuel flow and a piston 21 downstream of the element moves after seating of the element to reduce the pressure downstream of the element. The piston 21, which moves the element 19 from its seat 20, may be operated by a piston 22 actuated hydraulically by a plunger 25 reciprocated in timed relation with the engine. The plunger 25 is angularly adjustable and has a helical groove 27. A pressure relief valve 28 and a valve 28a operate such that the pressure acting on the piston 22 does not exceed or fall below predetermined pressures. The fuel flow to the injector 30, Fig. 2, is metered by a shuttle 37 which displaces fuel through the valve 18. The injector valve member 31 is biased closed by a pressure lower than the pressure in the accumulator 32, obtained by a pressure reducing valve 33 and acting through the passage 34. The piston 21 is moved to unseat the valve element 19 by fuel from the accumulator 32 under the control of a rotary valve 36 operated in timed relationship with the engine. The valve 36 also controls shuttle movement and at a predetermined shuttle position the groove 40 in the spool 39 causes the pressure applied to the piston 21 to change from accumulator pressure to the lower pressure in the passage 34 so that the piston moves and the element 19 seats. The shuttle 3 is moved in a direction towards a governor adjustable stop 41 by fuel from the accumulator 32 passing through the valve 36 and the non-return valve 38a. To supply a plurality of injectors 30, Fig.3 (not shown), a rotary sleeve valve (45) controls the operation of the shuttle 37 and respective valves 18 for each injector. A centrifugal governor (46, 47) with adjustable spring- loading controls the stop 41.