GB306477A - Improvements in or relating to fuel injection devices for internal combustion engines - Google Patents

Abstract

306,477. Simmen, O. Feb. 21, 1928, [Convention date]. Cylinders receiving liquid fuel. - A fuel-injection device comprises a chamber in which fuel accumulates under pressure and to which additional pressure is applied by external means so as to effect the airless injection of the fuel into the combustion chamber. As shown, the space surrounding the spring-loaded fuel injection valve 3 communicates with a chamber 21 in which is situated a spring-loaded plunger 7, the chamber 21 being connected through a non-return valve 12 with a conduit 13 connected to a fuel pump which draws its supply from a pressure tank. The chamber 10 containing the loading-spring 8 of the plunger 7 is connected through a conduit 11 to a controlling-device 2 which contains a spring-loaded piston valve 14 actuated by a cam 15 through a tappet 25. The controlling-device 2 is connected to the conduit 13 and to a conduit 17 which leads from the suction side of the pump and is provided with a pressure-equalizing chamber 18 and a pressure-reducing valve 19. When the piston 14 is in the position shown, the conduits 17 and 11 are in communication, and any pressure between zero and that existing in the tank supplying the pump is transmitted to the chamber 10 according to the setting of the valve 19. Owing to the pump pressure in the chamber 21, the plunger 7 yields to an extent determined by the difference in the pressures on its two faces. The setting of the valve 19 thus determines the quantity of fuel admitted to the chamber 21 and hence the quantity injected. When injection is to take place, the valve 14 is moved by the cam 15 into the position shown in chain lines, thus cutting off the conduit 17 and putting the conduit 13 into communication with the conduit 11, whereby the load upon the piston 7 is increased and the fuel is injected through the valve 3. In a multi-cylinder engine, one fuel pump is employed, the controlling-devices 2 are provided with a common pressure-reducing valve 19, and the cams 15 are arranged to act symmetrically with respect to the dead-centre position of the engine piston; if the engine is reversible, no form of reversing device is therefore necessary for the fuel-injection gear.