GB1300747A - Engine fuel control apparatus - Google Patents

Abstract

1300747 Regulating I. C. engines JOSEPH LUCAS (INDUSTRIES) Ltd 31 March 1970 [14 April 1969] 18905/69 Heading F1B Control apparatus for a shuttle-type fuelinjection metering pump 77, Fig. 1 comprises a three-dimensional cam 39 whose angular and axial positions are respectively alterable in accordance with first and second engine operating conditions, e.g. throttle setting, inlet vacuum or speed, a first cam follower 52 co-acting with the three-dimensional cam and moving a twodimensional cam 55 which is engaged by a second cam follower 8 and movable thereto in response to a third engine operating condition, the position of the second cam follower being transmitted to a control stop 77a on the metering pump. In use the inlet manifold vacuum is communicated by connection 26 to act on the left hand side of diaphragm 12 (in Fig.1), ambient air pressure being communicated through connection 79 to act on the other side of the diaphragm. With increasing inlet manifold vacuum the diaphragm assembly moves against spring 27 and rotates the three-dimensional cam 39 via link 37, plate 33, sleeve 31 and setscrew 41 to give an anticlockwise rotation of cam follower 52. Lever 49 is connected to the engine throttle control so that when the engine is accelerated the threedimensional cam 39 is moved axially via shaft 48, arm 49 and a roller engaged between flanges 44, 45, Fig. 2 (not shown) to give a clockwise rotation of cam follower 52 (as seen in Fig.1). Lever 64, Fig. 2 (not shown) is connected to the engine choke control so that movement of the latter to its starting position causes cam (62), Fig.5 (not shown), to rotate lever 60 against spring 61 and rotate bracket 66 clockwise, in Fig.1. Downward movement of member 75 permits increased fuel delivery. The angular position of the first cam follower 62 is transmitted to a cam 55 via bracket 54 and the position of the cam follower 8 depends on the position of the choke. The positions of roller 74 and member 75 depend on the positions of the throttle and choke controls and the pressure in the engine inlet manifold. In a modification the diaphragm assembly 9 responds to a pressure signal derived from engine speed.