GB604525A - Improvements in or relating to fuel injection pumps for internal-combustion engines - Google Patents

Abstract

604,525. Regulating. BEDALE, P. W., and HUGHES, J. O. P. Oct. 3, 1945, No. 25724. [Class 7 (vi)] A fuel injection pump for an internalcombustion engine has a metering jet controlled to give a flow in accordance with boost and back pressure and a second metering jet in parallel with the first controlled to give a flow proportional to the difference between a preselected datum temperature and the temperature in the induction pipe. A formula involving engine speed in addition to the above factors is given for the fuel flow. The fuel delivered to a chamber 14 by a vane pump 12 flows to a chamber 19 through an orifice 16 controlled in accordance with engine speed by a centrifugal governor 18 actuating a needle valve 17, and flows to the delivery chamber 22 through two orifices in parallel, the first controlled by a needle 24 connected to capsules 33 subject to boost pressure in the chamber 26 and atmospheric pressure through a pipe 29, and the second by a needle 25 operated by a capsule 30 in a liquidfilled chamber 31 connected by a pipe 32 to a thermometric bulb in the induction pipe. At the average temperature To of the operating range the needle valve 25 is partially open, rise of temperature closing it according to a factor To-Tc, where Tc is the induction pipe temperature. The needle valve 17 may be connected to a diaphragm subject to the fuel pressure in chamber 19 and adjustably loaded by a spring 20 to increase the flow at slow running, and the needle 24 may be contoured for enrichment at maximum power.