GB1394178A - Engine fuel injection apparatus - Google Patents

Abstract

1394178 Fuel injection pumps PERKINS ENGINES Ltd 10 Aug 1972 [16 Aug 1971] 38352/71 Heading F1A In liquid fuel injection apparatus comprising a rotary distributer type fuel injection pump 11 supplied with fuel by a feedpump 9 through a passage 17, 20 containing a metering valve 15 controlled by a speed governor 13, the injection timing is advanced in response to increasing feedpump pressure and is additionally advanced if light engine load conditions causes the governor 13 to reduce the opening of the metering valve 15 below a predetermined value. The injection timing is adjusted by a piston 40, Fig. 2, slidable in a bore 41 and having a transverse bore 43 which receives a radial pin 38 attached to the rotatable cam ring 28 of the pump. The feedpump pressure acts continuously on the left hand end of the piston 40 via a line 45, whereby, as the feed pressure increases the piston 40 moves against a spring 46 to advance the injection. The spring 46 bears against a loosely fitting plunger 49 in a chamber 47 connected to a tank 1 via a port 48. In turn the plunger 49 bears against a piston 51 urged to its extreme left position in a cylinder 50 by feedpump pressure communicated to a cylinder space 60 through the metering valve 15 and a passage 58, 59. When light load conditions causes the governor 13 to move the valve 15 below the predetermined value, the passage 58, 59 is connected by a passage (not shown) to the tank 1. This allows the pistons 40, 51 and the plunger 49 to move rightwards thereby additionally advancing the injection. The valve 15 comprises a valved spindle 19 rotatable by a rod 36 attached to a lever 34, the lever being loaded at one end by a spring 37 manually adjustable by a speed control lever 65 and at the other end by the movable sleeve 33 of the governor.