GB1366048A - Fuel injection pump for multi-cylinder internal combustion engines - Google Patents

Abstract

1366048 Fuel injection pumps ROBERT BOSCH GmbH 25 Aug 1972 [26 Aug 1971] 39632/72 Heading F1A In a fuel injection pump comprising a pumping piston 8 reciprocable and rotatable in a bush 19 by a cam plate 3 fixed to the piston, the cam plate 3 is urged into engagement with rollers 5 by springs 14 spaced at equal angles around, and parallel to the axis of the piston. Each spring 14 bears at one end against a body 15 and at the other end against a yoke 13 having a spherical surface which co-operates with a complementary surface on a washer 12 separated from a flange 9 on the piston by thrust washers 11. Pins 17 fixed to the body 15 pass through the springs 14 and apertures 18 in the yoke to prevent the latter from turning. During each suction stroke of the piston the pumping chamber 30 is filled with fuel from a space 26 through passages 27, 28 and whichever of grooves 29 in the piston is registered with the passage 28. Fuel is delivered via a delivery valve 23, passages 31, 32 and grooves 33, 34 in the piston, the groove 34 registering in turn with passages 35 each leading to an outlet 36. A sleeve valve 43 surrounds the piston in the space between the springs 14 and controls a spill passage 38 from the pumping chamber 30. The sleeve is movable axially to control the closing period of the spill passage and thus the quantity delivered and angularly to control the timing of closure of the spill passage and thus the commencement of injection. A pair of sleeves may be provided to fulfil the same function as the single valve sleeve 43.