Patent GB-906503-A (GB)
Title: Improvements in or relating to dual fuel internal combustion engines
IPC: F02D19/10
Filed: 1958-10-06
Abstract: 906,503. Dual-fuel engines; regulating; valvegear. SCHWEIZERISCHE LOKOMOTIVUND MASCHINENFABRIK. Oct. 6, 1958 [Oct. 10, 1957], No. 31789/58. Classes 7(2) and 7(6) [Also in Groups XXVI, XXVIII and XXIX] To effect operation on gaseous fuel with pilot oil injection, under control of a speed governor 48, Fig. 3, up to a maximum gas feed set during or before running by a hand wheel 50, and at higher loads to effect additional liquid fuel admission under control of the governor 48, cams 65, 66 and 70, 71 adjusted by the governor and wheel respectively act in pairs on followers 85, 87 linked to the control racks of pumps 24, 25, Fig. 1, individual to each working cylinder and respectively supplying a fuel injector 9, Fig. 2, and actuating the hydraulic valve-gear 20 of a gas inlet valve 18. The wheel 50, Fig. 3, acts through bevel gears on a sleeve 72 mounting, besides the cams 70, 71, a cam 74 controlling change-over between oil (diesel), gas and combined oil and gas operation, a cam 75 controlling a main gas valve and a cam 76 initiating lubrication at starting. The governor 48, Figs. 3 and 8, acts via an oil-pressure servomotor 49 on a shaft 64 mounting, besides the cams 65, 66, a servomotor stabilizing cam 67. The followers 85, 87, Fig. 3, act on the pumps 24, 25 via arms 84, 88 of shafts carrying arms 41, 45, Fig. 1, linked to arms 40, 44 of control-rack actuating shafts 39, 43. The pumps 24, 25 are of the type having rotatable plungers with helical spill grooves. Operation. The wheel 50 has a pointer which moves over a scale 81, Fig. 8. With the pointer directed as shown to the graduation 100 on a "GAS" scale section the cam 74 via linkage 92 lowers one end of a floating lever 56 fully and the servomotor power member 63 operates over an angle α in one half of its range under actuation of its control piston 57 by the governor 48 via a lever 55 pivoted at 46. The cams 70, 71 are then clear of the followers 85, 87 and the cam 65 gives pilot oil injection only and the cam 66 up to full gas admission as required. If the pointer is directed to an intermediate graduation, e.g. 50, on the "GAS" scale section, the cam 74 is set to allow extended movement of the member 63 over part of the other half of its range also and the cam 71 is rotated sufficiently to restrict the maximum gas admission appropriately whilst the cam 65 allows additional oil admission over the corresponding inoperative range of the cam 66, the cam 70 being again inoperative. If the pointer is directed to a graduation, e.g. 100, on a "DIESEL" scale section the cam 74 is set to give operation of the member 63 over an angle α in the said other half of its range only. The cam 65 then allows additional oil admission up to a corresponding limit set by the cam 70, whilst the cam 71 prevents gas admission. The governor 48 has a speed setting device 53. Mixing air and gas. Each cylinder has a gas inlet valve 18, Fig. 2, and a nozzle 15 through which air from a manifold 14 passes to mix with gas admitted via slots 16 by the valve 18 fed by a manifold 19. Indicating working conditions. Pointers 97, 98, Fig. 3, linked to the arms 41, 45 respectively, move over a scale 96 to show the amounts of oil and gas fuel being used. Wood gas from a generator or blast furnace gases may be used as the gaseous fuel. Specification 906,504 is referred to.