Patent GB-756254-A (GB)
Title: Fuel injection system for internal combustion engines
IPC: F02D1/00
Filed: 1954-06-25
Abstract: 756,254. Regulating. BENDIX AVIATION CORPORATION. June 25, 1954 [Aug. 31, 1953], No. 18727/54. Class 7(6) [Also in Group XXVIII] An engine driven supply pump 10 is connected to an injection pump 26 by a metering device comprising a main conduit 74 with a metering restriction 112, a first by-pass conduit 73, controlled by an engine variable for returning a portion of the unmetered fuel to a low pressure source and a second by-pass conduit 102 for returning a portion of the metered fuel to said source. The main conduit 74 includes a restriction 112 controlled by a needle valve 114 actuated by a device 120 in accordance with the temperature of the air in the intake pipe 60, the major portion of the fuel flowing through the restriction 112 being delivered through a passage 14 to a rotary distributer 24 which delivers the fuel to the inlet passages 38 of the injection pump cylinders 21 from which the fuel is fed under high pressure to the injectors 48 situated in the intake manifold 49. The supply pump 10 comprises a gear pump the drive shaft 16 of which drives a wobble plate 44 actuating the pistons 21 of the injection pump 26 and also drives a shaft 28 on which is slidably fixed the distributer valve 24 which is moved to the left against a loading spring 29 by the pressure in the passage 14 acting on the end thereof. The fuel flows through a port 34 into the hollow interior of the valve 24 and out through a port 33 therein to the pump inlet passages 38 which are closed during the pumping stroke of the pistons 21 by a helical land 32 on the valve 24. Movement of the valve 24 to the left due to an increase of fuel pressure in the passage 14 brings a wider part of the land 32 opposite the parts 38 which are thereby closed for a greater period during each pump stroke to increase the fuel delivered to the injectors on each stroke. The idling position of the valve 24 is controlled by spring-loaded abutment 27 which may be actuated by a lever 40 to move the valve 24 to a cut-off position in which a land 37 registers with the passages 38 and cuts off the flow of fuel thereto. A valve 84 in the by-pass 73 is controlled by a capsule 92 according to the pressure in the intake pipe 60, the valve 84 being closed as the intake pressure increases to reduce the flow through the by-pass and hence increase the flow through the main conduit 74. A by-pass 142 which joins the by-pass 74 at 76, is opened at low and medium speeds by a spring-loaded valve 144 which is moved by the fuel pressure in conduit 146 at high speeds to close the by-pass 142. The pressure in passage 76 downstream of the valve 84 and jet 142 is maintained equal to that in the by-pass 102 downstream of the orifice 112 by a valve 98 controlling the connection of the passage 76 to a passage 78 which delivers the by-passed fuel back to the inlet of the pump 10. The passage 102 leads to a by-pass passage 106 containing a restriction 107 through which a predetermined portion of the fuel metered through orifice 112 is bled back to the inlet of the pump 10. The engine may be supercharged by a blower.