Patent GB-1355922-A (GB)
Title: Combustion machines
IPC: F02B1/04
Filed: 1972-06-23
Abstract: 1355922 Fuel injection apparatus J ZEYNS and H ENNEKING 23 June 1972 [9 July 1971 15 Dec 1971] 29574/72 Heading F1B I. C. engine fuel distributing device comprises an adjustable valve plate 19 arranged in the air inlet channel 18 and which is acted on by the incoming combustion air in opposition to a restoring force, movement of the plate 19 altering a throughput opening 15 in a fuel control line by means of a control member 13, in proportion to the amount of air flowing in the combustion air channel, whereby a fuel control pressure is produced in the fuel control line 9 which is connected at its upstream end to the fuel pump 1 via an amplifying resistance 7 and is connected at its downstream end via a difference pressure regulator 25 to the fuel supply tank, the fuel control pressure actuating a plurality of pressure regulators 53 each associated with a fuel injection valve through which the fuel passes via measuring resistances 55, in which the outflow cross-section is adjusted in dependence upon the fuel control pressure so that the pressure drop at the measuring resistance is equal to the pressure drop at the amplifying resistance. The valve plate 19 is mounted on the control member 13 and has an annular groove 14 which overlaps, by a varying amount as the member 13 reciprocates, an axial slot 15 in the control cylinder 12, thus varying the rate of flow through the fuel control line 9. A duct 21 leads the fuel to a chamber 23 of the difference pressure regulator 25. The effective opening of the upper end of a duct 27 is controlled by a diaphragm 39, the upper surface of which is subject to the pressure of the fuel in the line 9. The duct 27 leads to an overpressure regulator 29 which prevents evaporation of the fuel. A duct 33 conveys fuel from the line 21 to a chamber 35 where it acts on the end face of the member 13 in opposition to the force of the air flow on the plate 19, and in the same direction as a spring 37. To ensure that the correct overpressure acts in the space 35 under all operating conditions an auxiliary duct 47 containing a throttle valve 49 leads from the fuel line 5 to the lower chamber 23 of the difference pressure regulator 25 and allows a small balancing flow. In a modification, Fig. 2, (not shown) the duct 33 leading to the pressure space 35 is connected to the duct 27 downstream of the regulator 25, instead of to the duct 21. A magnetic valve 65 in the fuel line 5 closes on skidding or other uncontrolled movement of a vehicle. A further valve (67) Fig. 3, (not shown) is provided in the fuel control line and has connected in parallel with it a laminar resistance (7a). The valve (67) is moved to the closed position when a bi-metal switch (70a) indicates a cold engine, or when the throttle pedal is fully depressed. The additional resistance thus introduced into the fuel control line causes a drop in the fuel control pressure and hence enrichment of the mixture. The laminar resistance 7, Fig. 4, consists of two pistons 173 and 177 mounted on a common rod 175 and operating in a stepped cylinder 171. Fuel flows through the pistons and around the piston rod, the radial clearance 191 being about 80Á. The cylinder is made of brass and the piston assembly of steel so that consequential dimensional changes compensate for ambient temperature changes. Additional enrichment can be effected by a by-pass line 77. Fig. 3 (not shown) connecting the fuel control line to the line 21 and including a temperature responsive valve which closes with increasing engine temperature. The air-fuel ratio can also be adjusted by providing an aperture in the plate 19 which can be closed progressively by a shutter which is fixed in the adjusted position. Alternatively a by-pass pipe can be provided around the plate 19, the by-pass containing a valve 91 which is actuated by a temperature sensitive element and opens as the engine temperature rises.