GB1342711A - Liquid fuel injection pumping apparatus - Google Patents

Abstract

1342711 Fuel injection pumps C A V Ltd 26 May 1971 [30 May 1970] 26171/70 Heading F1A A fuel injection pump is provided with temperature sensitive means operable to cause retardation in the timing of injection and excess fuel supply when starting an associated engine from cold. The pump is of the kind, Fig.1, comprising a rotary distributor 11 having radial cylinders 12 in which pumping plungers 13 are reciprocated by indirect co-operation with a rotatably adjustable cam ring 17. To control the quantity of fuel admitted to the cylinders 12, a metering chamber 22 containing a freely slidable piston 21 is provided. The chamber 22 receives fuel through a port 23 during the plunger's injection strokes and is subsequently expelled through the port 23 and a passage 20a into the cylinders 12 during the suction stroke. Excursion of the free piston 21 and the angular position of the cam ring 17 are determined by the axial positions of spring loaded pistons 27, 18, respectively. Both pistons 27, 18 move in response to a speed dependent fluid pressure supply (not shown). During cold start-up a wax type temperature sensitive element 40 moves a cam member 38 to a position in which pins 33, 34 allow pistons 27, 18 to assume their excess fuel and retarded injection positions, respectively. In an alternative arrangement, Fig.4 (not shown) a temperature element (55) causes a throttle valve (50) to delay the application of the speed dependent supply to the pistons 18, 27.