GB561017A - Improvements in charge forming devices for internal combustion engines - Google Patents

Abstract

561,017. Spray carburetters. BENDIX AVIATION CORPORATION. Aug. 7, 1942, No. 11080. Convention date, Dec. 29, 1941. Addition to 523,895. [Class 7 (iii)] In the charge forming device as described in the parent Specification, the fuel flow to the fuel conduit 80 is controlled by an element or valve 95 actuated by a sealed capsule &c. 96 subjected to pressure which varies in accordance with the velocity of the air flowing through the main air passage 10 and with the density of the air. Air is supplied through a scoop turned in the direction of motion. Two diaphragms 43, 44 mounted on the spindle 50 of a slide valve 52 control openings 53 through which fuel flows from a pump 26 to a chamber 38 separated from a chamber 39 by the diaphragm 43. The chamber 39 fills with fuel which has passed from the chamber 38 through a restricted orifice 62 and outlet 59 controlled by a hand-operated valve 67, the arrangement resulting in the chamber 39 containing fuel at a lower pressure than that in the chamber 38 so that the valve 52 is urged towards its closed position. This action retards the opening of the valve by differential pressures applied to the two sides of the diaphragm 44 which on its near side is exposed to the pressure prevailing at the throat 23 of a small venturi 22 in the air passage 10 and at its other side to a chamber 19 formed in the outer surface of a main venturi 18 and kept by pipes 20 at the pressure in front of the venturi 18. Passages 85, 86 connect the respective sides of the diaphragm 44 to the throat 23 and chamber 19 and are interconnected by a bleed 90. The pressure which the chamber 19 communicates to the diaphragm 44 through the passage 86 is modified automatically by the valve 95 on the capsule 96, the capsule being housed in a chamber 97 communicating through an aperture 98 with the air inlet 10 and with the passage 85 through a port 99. The valve 95 has a byepass 88 controlled by a valve.92 which is manually actuated simultaneously with the fuel valve 67, both being opened to secure a free flow of fuel. During idling, a valve 69 linked to the throttle 15 almost closes the outlet 59. In modifications, the chamber 97 communicates with the throat of the main venturi instead of with the throat 23 of the venturi 22, or the chamber 19 is divided into two compartments, one opening into the entrance to the venturi and the other communicating with the throat and the chamber 97 communicates with both these compartments, the smaller venturi 22 being omitted in one construction.