GB827707A - Improved apparatus for forming combustible charge for an internal combustion engine - Google Patents

Abstract

827,707. Spray carburetters. GENERAL MOTORS CORPORATION. July 18, 1958 [Aug. 1, 1957], No. 23100/58. Class 7(3) A metering valve 48, Fig. 2, metering fuel supplied under pressure to one or more fuel injection nozzles 60 is controlled in accordance with throttle valve position and engine speed. The metering valve is connected by a link 129 to a lever 136, Fig. 1, which is adjusted through further levers by a cam 162 on the throttle valve spindle and by a rod 176 actuated by a centrifugal governor 172, Fig. 2, At small throttle openings, e.g. up to 10 degrees, the lever 192, on which the centrifugal governor acts through a pin and slot connection 188, is aligned with rod 176 so that the governor has no effect on the metering valve control lever 136. At larger throttle openings a cam 200 on the throttle valve spindle tilts the lever 192 so that the movements of the governor rod 176 are transmitted through lever 192 and pin and slot connection 146 to lever 144 and thence to the metering valve lever 136. At a predetermined speed, adjustable by a throttlevalve-controlled cam 216, the pin 146 enters a circular part 210 of its associated slot to prevent any further adjustment of the metering valve by the governor. The pivot 138 of metering lever 136 is adjusted by a barometric capsule 230 and the pivot of lever 152 is adjusted by a diaphragm 250 actuated by intake pipe suction to produce enrichment at high power outputs. A cold running arrangement, comprising a bimetallic coil 274 and suction operated piston 276, adjusts a lever 278 to cause a member 290 to hold the throttle valve 166 slightly open and a member 304 to move lever 152 to enrich the idling mixture. An abutment 280 on lever 278 also co-operates with an abutment 282 on the rod 154 to limit the opening movement of the throttle valve when the engine is cold. The metering valve is supplied with fuel by a high pressure pump 16, Fig. 2, fed by a low pressure pump 12, a pressure operated valve 30 cutting off the outlet 20 of the pump 16 at starting so that the fuel is supplied direct to the metering valve by the pump 12. The pressure drop across the metering valve is maintained constant by a by-pass valve 98 actuated by the pressures upstream and downstream of the valve. An electrically operated cut-off valve 130 closes the fuel pipe to the nozzle when the engine stops. Passages 66, 68, supply fuel to recesses to lubricate the valve 48, the fuel leaking past the valve being collected and returned through passage 72.