GB1219767A - Liquid fuel injection pumping apparatus - Google Patents

Abstract

1,219,767. Fuel injection pumps. C.A.V. Ltd. March 27, 1968 [April 17, 1967], No. 17483/67. Heading F1A. Shuttle pistons 19, 20 are slidable in a bore 15 in a rotary distributor 11 having a delivery passage 17 and inlet passages 25, 26 leading to the space between the shuttles and the discharge chamber respectively. In one position of the distributor the passages 25, 26 are connected through throttle passages 29a, 30a, to the output of feed pump 21 to move the shuttles to the left until shuttle 19 engages stop 41; the leftward movement of the shuttle 20 is controlled by the throttle and determines the quantity which will be discharged. Inward movement of the plungers 13 on further rotation of the distributor hydraulically moves the shuttle 19 to the right and this movement is transmitted through the liquid column between the shuttles to shuttle 20 which discharges fuel through the delivery passage 17. When shuttle 20 opens passage 33 liquid is discharged and shuttle 19 engages shuttle 20 to continue its movement until it engages stop 16. Excess liquid displaced by plungers 13 opens valve 35 in shuttle 19 and flows to passage 33. In order to vary the timing of injection in accordance with speed the outlet pressure of the feed pump is made speed sensitive and acts on a valve 39 to supply extra liquid to the chamber 12 to move the plungers 13 further outwardly after the shuttle 19 has engaged the stop 41.