GB1428667A - Device for regulating the delivery of a fuel injection pump of an internal combustion engine - Google Patents

Abstract

1428667 Regulating IC engines SIGMA DIESEL 22 May 1973 [6 June 1972] 24489/73 Heading F1B A device for regulating the delivery of a fuel injection pump for an I.C. engine comprises a centrifugal governor 1a, Fig. 1, adapted to be driven by the engine, including a pusher element 3a adapted to slide along an axis of a drive-shaft 2a of the govenor in response to speed changes; a regulating member 19a for adjusting the delivery of the injection pump being pivotally connected to one end of a transmission lever 70 whose other end is pivotally connected to an intermediate lever 30a and whose middle portion is mounted on pivoting means m, 71, Fig. 3. The lever 30a is mounted intermediate its ends on a first sleeve 4b, movable with the pusher element 3a, a second sleeve 4a in which sleeve 4b is slidable being connected for translation with the pusher element 3a. First resilient means (springs 13a, 14a), whose compression is determined by the postion of an accelerator lever 15a, co-operate with the first sleeve 4b, and second resilient means (spring 29a) act between the first and second sleeves to permit relative movement of the sleeves, causing rotation of the levers 30a and 70 and movement of regulating member 19a. The pivoting means m, 71 can be actuated to displace the geometric axis of rotation of the lever 70 with respect to a casing 9a of the device to move the regulating member in response to a controlling fluid-pressure, which may be the pressure of air delivered by a turbocompressor to the engine or gas or liquid supplied by an auxiliary source which may be responsive to an engine operating condition. The pivoting means is actuated by a jack 153, Fig. 4, a piston 156 of which is movable against a spring 164 by fluid admitted via duct 169. In a modification (not shown) the jack 153 may be associated with a device sensitive to atmospheric pressure variations. On starting, the pusher element 3a is held in its leftmost position by spring 5a, as are sleeve 4b and lever 30a. The upper end of lever 70 and the member 19a are fully to the right to give maximum fuel per revolution. When the engine speed reaches N', Fig. 11, the element 3a and sleeve 4b move, without compression of spring 29a, to the right compressing spring 5a until shoulder 50 abuts shoulder 138 of bush 132 at engine speed N o . This displaces lever 30a without rotation as axes 31a and 44 are moved together so as to turn lever 70 anti-clockwise and move member 19a to the left. The springs are such that as engine speed increases, spring 29a yields first, then spring 134, then springs 13a, 14a. At speed N 1 , spring 29a yields so that sleeve 4a moves to the right and sleeve 4b remains stationary causing lever 30a to rotate anticlockwise and hence lever 70 to rotate clockwise thereby increasing the fuel delivery. This continues up to speed N 3 . In addition, from speed N 1 to speed N 2 , the pressure of air from the engine supercharger applied below piston 156 causes it to rise compressing a spring 164 and rotating the axle 71 around pivot 139 which causes a clockwise rotation of lever 70 around pivot 72, thus increasing the fuel delivery. At speed N4 spring 134 yields, so sleeve 4b approaches cup 6a and also moves sleeve 132. As sleeves 4a, 4b are equally displaced, the lever 30a is moved without rotation so rotating lever 70 anti-clockwise and decreasing the fuel delivery. At speed N 5 , shoulder 138 of bush 132 abuts on bush 130 and, as the speed increases further, springs 13a, 14a yield so that the pump delivery diminishes rapidly.