GB1095757A - Improvements in fuel injection pumps - Google Patents

Abstract

1,095,757. Fuel injection pumps. SOCIETE INDUSTRIELLE GENERALE DE MECANIQUE APPLIQUEE. Dec. 3, 1964 [Dec. 4, 1963], No.49233/64. Heading G1A. In the fuel injection pump shown in Fig. 1, a shaft 4, driven by an I.C. engine (not shown), is formed with a disc 4a which carries a cam-ring 7, the lobes of which operate main pump pistons 5, Fig. 3, through rollers 11 and push pieces 12 against return springs 13. From an inlet 18, fuel is fed to the main pump by an auxiliary pump 17 through a pipe 19, inlet 21 and an annular groove 22 formed between fixed members 1a and 1b of the main pump body. The groove 22 communicates through radial holes 23, the number of which equals the number of cylinders of the I. C. engine, with the bore in which rotates a distributing valve 2 formed with suction and delivery ports 24 and 26 respectively, having oppositely inclined portions 24a and 26a which communicate with an annular groove 25 provided in the valve 2 and in communication with the main pump cylinders 6. Delivery from the main pump is effected through passages 8 and 9 via check valves 10. Excess fuel delivered by the auxiliary pump is discharged from the groove 22 through a valve, Fig. 2 (not shown), to a tank or the fuel inlet 18. Since the inclined portions 26a, 24a determine respectively the beginning and end of the periods of injection to any one cylinder of the I. C. engine, and since these portions are oppositely inclined, the main pump delivery may be regulated by axial movement of the valve 2. Similarly, variation of the angular position of the valve 2 with respect to the shaft 4 regulates the timing of injection. Both these regulations are effected by a governor comprising two masses 30 pivoted about pins 31 in a flange 32 of the shaft 4. Radially outward movement of the masses 30 results in a push piece 33 moving a member 27 to the right against a spring 28. The member 27 is splined to the shaft 4 and is slidably secured to the valve 2 by a pin 29 engaging a helical slot in the valve. Axial movement of the member 27 therefore effects advance and retard regulation. However, axial movement of the valve 2 is opposed by resilient means arranged to yield after the spring 28, and comprising springs 34 acting on the valve 2 through a lever 39 provided with a resilient plate 38. The compression of the springs 34 is varied by a lever 36 acting on a cup 35 in dependence upon the setting of the I. C. engine throttle valve. Lubricant from inlet 45 is fed by a pump 43, similar to the auxiliary pump 17 and separated therefrom by seals 44, through a port 46 to the interior of the fuel injection pump casing, excess oil being discharged through a valve 47.