GB707217A - Improvements in fuel injection pumps - Google Patents

Abstract

707,217. Speed governors. MONO-CAM, Ltd. June 14, 1950 [June 17, 1949], No. 16237/49. Class 57 [Also in Group XXVIII] In a fuel injection pump having a plurality of plungers 7 whose effective delivery strokes are controlled simultaneously by a common regulating member 14 which adjusts the point in the stroke at which fuel is spilled from the cylinders 5 into a chamber 3 communicating with the pump inlet or other low pressure region, the chamber communicates with the low pressure region through a restriction 34 so that a pressure, which is a function of the speed and loading of the engine supplied by the pump, will be built up in the chamber, and a pressure responsive flexible member 38 is exposed to the pressure and causes the regulating member to reduce. the delivery as the speed increases. The pump is of the kind described in Specification 580,354, [Group XXVIII), in which the plungers are actuated by an axial cam through a push rod 23 and in which sleeves 17, secured to the axially movable regulating member 14, co-operate with the radial spill bores 31 in the plungers. The restriction is provided by an annular space between a bore 34, communicating with an inlet chamber 10, and a restrictor pin 37 which may be straight or tapered and may be spring loaded or adjustable manually in order to vary the flow resistance. The pin may be of a metal having a higher expansion coefficient than that of a sleeve 32 containing the bore in order to compensate for lower fuel viscosity at higher temperature. A metallic bellows 38, secured to the regulating member and to a fixed partition 20, is subjected externally, to the pressure in chamber 3 and its interior is connected with the intake manifold of the engine through passages 54, 55, 56, 57 in order to provide an additional governing effect. The bellows may alternatively be connected to the engine exhaust and act on the member in the opposite direction. The regulating member, which is loaded by a spring 50 is also adjustable by a lever 41 through a rod 39 to determine the delivery setting of the pump. Spacing washers 52 between the rod and the member are used to vary the spring loading. A collar 46 on the rod co-operates with a shoulder 47 and with an adjustable sleeve 48 to limit the minimum and maximum delivery respectively. Specification 707,218 also is referred to.