GB943370A - Fuel injection apparatus for internal combustion engines - Google Patents

Abstract

943,370. Fuel injection pumps. KLOCKNERHUMBOLDT-DEUTZ A.G. April 5, 1962 [April 7, 1961], No. 13140/62. Headings F1A and F1B. In a fuel injection pump having a piston 5 operated by a piston 13 which is moved on the suction stroke by pressure liquid supplied by a pump 1 through passage 6 to a space 12 and on the injection stroke by a spring 14 when the pressure in chamber 12 is released through pipe 36, a valve 4 controls the pressure supply and release pipes 6, 36, and the release pipe 36 contains a throttle which increases in area as each injection progresses. The pump 1 supplies pressurised fuel through pipe 7 to the pump inlet port 30 and the pump spill port 22 is connected to a drain pipe 17. The valve 4 actuated by an engine driven cam 33, opens passage 6 to the chamber 12 at the end of each injection so that piston 13 is forced down. When the valve 4 is lifted to initiate injection, passage 6 is closed and a tapering groove 35 connects chamber 12 to the release pipe 36, whereby spring 14 starts to raise piston 13 and pump piston 5. As valve 4 rises, the increasing depth of groove 35 increases the rate of escape of liquid from chamber 12 and the rate of injection increases. The valve 4 is guided by a pin 37 which may be adjustable. In a modification, Fig. 3, the groove 35 is of constant depth and the variable throttle in the release pipe 36 is formed by a tapering groove 49 in the wall of piston 13. The piston 13 may be adjusted angularly by an eccentric pin 53 to vary the effect of groove 49, and this adjustment may be effected by the pump control rod 58, Fig. 6, which conjointly adjusts the angular position of the pump piston 5 through an eccentric pin 60. A pump unit as shown in Fig. 6 may be combined with an injection nozzle for each engine cylinder, and the separate control rods 58 may be connected to separate hydraulic pistons which are controlled simultaneously by an hydraulic control system.