GB795350A - Improvements in or relating to fuel injection systems for diesel and like engines - Google Patents

Abstract

795,350. Fuel - injection systems; valves. SIMMS MOTOR UNITS, Ltd., and DUNN, H. G. Feb. 21, 1956 [Feb. 21, 1955], No. 5156/55. Class 7(3) and 7(6) In a multi-cylinder engine a pump 13, closely associated with each injector 12, circulates fuel through passages 25, 27, in the injector to a by-pass pipe 32 ... 35, Fig. 2, leading to the fuel reservoir, injection occurring when the by-pass pipes are temporarily blocked in sequence by a rotary control valve. In Fig. 2 the by-pass pipes 32...35 of separate injectors each having an injection pump 13 formed therewith as a unit, are connected to ports 46 controlled by a rotating valve 39 having an annular recess 47 therein connected by passages 48, 49 to a return pipe 54 leading to the reservoir, a raised land 53 serving to block each port 46 in succession at the required moment for injection. The valve 39 is splined to a drive shaft 37 and the land 53 is wedge shaped to vary the period of injection when the valve 39 is moved axially by a yoke 41 controlled by a governor. The pumps 13 are supplied by a low pressure feed pump and each by-pass pipe 32...35 contains a non-return valve 29. The circulation of fuel through the passages 25, 27 cools the injector. In a four-stroke engine each pump plunger preferably makes one delivery stroke for each two revolutions of the engine; alternatively each plunger may make a delivery stroke for each engine revolution, alternate strokes serving only to circulate fuel through the injector and not producing injection. It is stated in the Provisional Specfication that a single pump may replace the separate injector pumps 13.