GB1201347A - Electronic fuel injection control device - Google Patents

Abstract

1,201,347. Control of fuel injectors, electrically. SOC. DES PROCEDES MODERNES D'INJECTION SOPROMI. Sept.29, 1967 [Sept.29, 1966], No.44563/67. Heading G1N. [Also in Division H3] In a fuel injection control system for an I.C. engine, electromagnetic injector valve coils 126, 127, 128 Fig.4 are sequentially actuated in correspondence with respective flexible switches 103, 104, 105 Fig.3 operated by a pick-up on a rotary engine member e.g. a cam-shaft. Closing of any switch causes a pulse through transformers 106 or 107 or 108 also 109 from a D.C. source 101, 102 (e.g. vehicle battery), and corresponding secondary pulses fire thyristors 130, 131 also one of thyristors 122, 123, 124 to energize a respective coil admitting fuel to the appropriate cylinder. The operation of a switch (e.g. 103), starts an injection timing circuit, including C134, UJ transistor 135 and a variable resistor R133 which is controlled by one or more engine parameters e.g. pressure in inlet manifold or speed of rotation. A unit 136 (not described) also operates to correct the injection time as a function of engine parameters. Thus switching of 103, initiates the changing of C134 so that at the end of a certain time equal to the injection time, the charge on C134 is sufficient to fire UJ 135 and produce a pulse through a transformer 137 primary. A resulting secondary pulse fires an extinction thryistor 129 to turn OFF Th 131 by making the charge on C125 twice the supply potential. Thereby the injection period is terminated. In the initial part of the injection period a charge on C125 is added to the supply voltage through Th 130, the diode 120 being biased off, and the sum voltage is applied to the appropriate coil to make the injector open more rapidly. When C125 has discharged sufficiently Th 130 automatically extinguishes and diode 120 conducts to energize the injection coil. Subsequently Th 129 is turned ON as described above. Magnetic energy remaining in an injector coil after Th 131 is extinguished is recovered as potential energy in C125 and serves in the succeeding cycle to open the corresponding injector more rapidly. Specification 1,201,348 is referred to.