Patent GB-494954-A (GB)
Title: Improvements in or relating to speed-responsive governors for controlling fuel injection systems for internal combustion engines
IPC: F02D1/00
Filed: 1937-05-01
Abstract: 494,954. Fuel - - injection - control systems for internal-combustion engines ; gear-wheel pumps. ATTWOOD DIESEL EQUIPMENT CO., Ltd., GORDON, H., and ATTWOOD, S. H. May 1, 1937, No. 12503. [Class 135] [Also in Group XXVI] A fuel-injection system for internal-combustion engines of the kind in which fuel at injection pressure is admitted to the engine cylinders by means of injector valves operated mechanically or hydraulically in such wise that there is no interdependence between the cycle of operation of the pump producing the injection pressure of the fuel and the valve operating means, includes a cam plate having cam forms adapted for controlling the timing and/or the period of injector valve opening and/or the pressure at which liquid fuel is supplied, said cam plate being operated by a governor of any appropriate construction responsive to engine speed. In the form shown in Figs. 1 and 2 the cam plate 2 is operatively connected with a speed governor 1 and has cam forms 3, 4, 5, 6 of which the cams 3 and 5 are adapted to control respectively the time of the commencement and the length of the injection period. The cam 6 is so shaped in relation to the cam 5 that the period is materially reduced or cut out upon attainment of a predetermined limiting speed. The cam 4 is engaged by a pin 27 on an arm 28 which is pivotally mounted upon a shaft carried by a regulating plunger 29 of a pump as described in Specification 494,952, [Group XXVIII], and operates to control the injection pressure of the fuel. The cam 3 is engaged by a pin 7 in a crank-shaft 9 having a toothed sector 10 which meshes with teeth on a sleeve 12 carrying a time cam ring 11a. The cams 5 and 6 engage pins 13 and 26 on a crank arm 14 secured to a half period control spindle 15 having a helically toothed portion 16 meshing with a pinion on a shaft 18. The shaft 18 is manually adjustable longitudinally and carries a second pinion 19 meshing with a helically toothed portion 20 of a second half period control spindle 21 which has a toothed sector 22 meshing with teeth on a sleeve 24 to which the period cam ring 25 is secured. The rings 11a and 25 form part of a distributer as described in Specification 494,953, [Group XXVII]. Fig. 4 shows a combined cam plate and speed responsive governor of the fluid type. A pinion 31 fast on a shaft 30 driven at or proportional to engine speed drives an internally toothed ring 32 of larger diameter rotatably mounted in a casing itself mounted for limited rotary movement in a fixed casing 44 against the action of a spring. The crescent-shaped space between the two toothed members is occupied by a filling piece except at the ends where suction and delivery spaces are provided. The pump casing which is turned against the spring by the reaction pressure as the speed increases is formed with a toothed boss 41a on which the cam plate 49 is mounted and which operates through a differential toothed quadrant and rack to adjust a tapered valve in the pump outlet. In the form shown in Fig. 9, the pump comprises three gear pumps formed by pinions 56, 57, 58 rotatably mounted in sockets formed in a casing 64 carrying the cam plate and meshing with a central driven pinion 55. The gear pump 55, 56 forwards oil from the inlet 69 through a passage 67 to the gear pump 55, 57 which in turn forwards the oil through a passage 68 to the gear pump 55, 58 which discharges the oil through a restricted passage 75 into a recess 74. Excess oil from the passage 67 passes through a passage 73 into a recess 72 which together with the recess 74 communicate with a groove provided with a relief valve and forming the inlet to a high pressure pump. The casing is turned by reaction pressure against the action of a spring acting through a toothed quadrant and pinion to adjust the position of the cam plate. In a further form a gear pump delivers oil to an oscillating vane motor geared to the cam plate. Rotary vane or multi-radial-cylinder pumps may be employed. A damping device comprising a spring loaded piston may be fitted to damp out any pressure ripples developed by the governor pump. Specification 494,955, [Group XXVII], also is referred to.