Patent GB-584130-A (GB)
Title: Improvements in fuel-injection systems for internal-combustion engines
IPC: F02M57/02
Filed: 1944-02-11
Abstract: 584,130. Oil engines. MUNTZ & CO., Ltd., A., BEALE, E. S. L., and FARMER, H. O. Feb. 11, 1944, No. 2590. [Class 7 (iii)] In a free-piston or other compression ignition engine having an injection nozzle 17, Fig. 1, controlled by a valve 19 normally held seated by fluid pressure in a loading chamber 22, the valve is raised by pressure of the fuel in a passage 33, leading from an accumulator 24, when the pressure in the chamber 22 is periodically released. A "jerk" pump having an inclined piston face, and rotation of which times the initiation of the pumping action, supplies fuel through a pipe 23 to the loading chamber 22 and the rising pressure opens a valve 29 in a passage leading to the space below the piston 25 of the accumulator 24, raising the piston against pneumatic pressure applied to a piston 26 contacting the upper end thereof. The piston 25 uncovers a port 32 leading to an outwardly opening valve 34 controlling the fuel delivery passage 33. At the appropriate time, the "jerk" pump pressure is released, and the reduced pressure in the loading chamber 22 permits the valve 29 to close and the fuel pressure in the passage 33 to open the injection valve 19. As the fuel is discharged, the accumulator piston 25 descends closing the port 32, but fuel around the valve 34 escapes via a spill port 36 in the wall of the accumulator 24, a groove 38 in the piston 24 and a further spill port 37 to the loading chamber 22. The reduction in pressure closes the valve 34, a mask 35 thereon closing the escape passage before the head is seated and extracting fuel from the passage 33 to effect a positive reduction of pressure therein. The pump may supply simultaneously several injectors delivering into the same combustion space the fuel flow in the inlet pipe of each injector being evened out by a restricted portion which is provided with a byepass containing a relief valve to ensure that the fall of pressure is rapid. The pump may be of the constant delivery type and the fuel supply be controlled by manual depression of the accumulator pistons 26. The accumulator plungers 25 may rise a fixed distance and control be effected by providing a sloping face to the plunger near its head so that rotation of the piston varies the time of uncovering of the spill port 36 or as shown in Fig. 6, an additional spill port 49 co-operates with an inclined surface 50 on an intermediate part of the plunger 25B, the space below the inclined face communicating with the accumulator space by a passage 51 in the plunger. Each injector may have a positive-displacement selfacting metering device, fuel being admitted through a port 58, Fig. 7, to depress a sleeve valve 53 closing ports 54 therein and then to depress for a predetermined distance a plunger 52 within the sleeve to deliver the fuel charge, springs restoring the sleeve and plunger to their original positions when the pressure is released. A separate injection timing valve may be used and may be cam actuated or be operated by combustion pressure directed against a diaphragm connected to the stem of the timing valve. Specifications 578,436 and 579,734 are referred to.