GB744806A - Control mechanism for fuel injection pumps for internal combustion engines - Google Patents

Abstract

744,806. Regulating. S.U.CARBURETTER CO., Ltd. Aug. 5, 1954, No. 22738/54. Class 7(6) The output of a fuel injection pump 6 is controlled according to the temperature and pressure of the air in the induction pipe 2 by a capsule 16 in an enclosure 15 which is connected by a pipe 14 of relatively large cross-section to the throat of a. venturi 13 downstream of the throttle valve 11 and by a pipe 17 of relatively small cross-section to the induction pipe downstream of the venturi 13. The pump 6. which may be as described in Specifica-- tions 533,596 or 552,547 [both in Group XXVIII] and which feeds injection nozzles 9 situated adjacent the inlet ports 5, is first adjusted to provide a correct fuelair ratio when the engine is running at the speed at which the mass of air induced per cycle is a maximum. When the engine speed increases the increase in the richness of the fuel-air mixture, due. to a decrease in the volumetric efficiency of the engine, is compensated for by the increase in suction at the venturi throat 13 Which -reduces the pressure, in the chamber 15 and reduces the fuel: supply. At idling a throttling device 18, operated from the throttle valve control means 23 by a cam 22, restricts communication of the pipe 14 with the venturi 13, and over-richness of the mixture is prevented by producing a high suction in the' pipe 14 by means of a venturi 25 in a by-pass 24 around the throttle valve, the: suction at the venturi 25, which at idling is higher than that in the induction pipe 2, being transmitted to the pipe 14 through pipe 26 containing an adjustable restriction 27.