GB657759A - Fuel injection devices for internal combustion engines - Google Patents

Abstract

657,759. Valves; regulating. RETEL, J. M. R. March 8, 1948, Nos. 7054 and 7055. Convention dates, March 7, 1947, and Feb. 25,1948. [Class 7(vi)] [Also in Groups XXVIII and XXIX] In an injection device for internal-combustion engines, a pump delivers to a fuel storage chamber 'connected through a cylindrical distributing valve to .the injectors, the quantity of fuel delivered being varied by adjusting the longitudinal position of the valve solely by the pressure in the storage chamber. Fig. 1 shows a fuel-injection pump comprising a number of parallel cylinders containing pistons 11 actuated by a swashplate 21. Each piston is provided with a valve 12 and fuel is drawn through the inlet 15 and valve 12 and delivered through the valve 17 and duct 10 to the storage chamber 18 containing capsules 19. A rotary distributing valve 34 is driven by the shaft 26 and fuel from the chamber 19 passes through the bore 58 to a port 40, duct 42 port 44, bore 45 to one or more ports 46 which align during rotation with one br more ports 47 leading to the engine cylinders. The rotary valve is loaded by a spring 36 and the pressure in the chamber 18 acts against this spring to adjust the valve axially, the ports 40, 44 in the valve have inclined edges so that as the valve moves axially, the time of the beginning of injection and the duration of the injection are varied in accordance with the pressure in the chamber 18. The end 55 of the valve is reduced to form a dashpot by arranging a spring-loaded sleeve 54 to surround it so that flow from the chamber 59 is throttled. The stroke of the pump pistons may be varied by adjusting the angle of the swashplate. Various arrangements of the ports in the rotary valve are described to suit engines with various numbers of cylinders. In the arrangement shown in Fig. 7, the storage chamber 18 is fitted with a relief valve 122 loaded by a spring 123 adjustable by a bolt 130. The chamber 125 is supplied with fluid under pressure and acts on the underside of plate 128 carried bv bellows 126 to varv the effective loading of the spring 123. This fluid may be sumpplied by a separate pump having an adjustable byepass valve. The fuel passes the valve 122 and passages 127 to the outlet 131. When the pressure of the fuel is used for regulating purposes, the bellows 126 and passages 127 are omitted and an adjustable valve is provided on the outlet from chamber 125. The duct 129 is provided with an adjustable valve for setting the fuel supply at idling speeds.