Fuel injection systems for internal combustion engines

1,088,883. Regulating I. C, engines. ASSOCIATED ENGINEERING Ltd. Jan. 15, 1965, No. 1976/65. Divided out of 1,088,502. Heading F1B. In a fuel injection system for an internal combustion engine in which pulses are supplied to the solenoids of electromagnetically actuated fuel valves, each solenoid is connected in series with a separate electronic gating device operated by triggering pulses. The gating devices may be silicon controlled rectifiers. In a first embodiment the gates are controlled by a mechanical, optical or electrical distributer which also triggers a pulse generator. In a modification a normally conductive transistor is connected in series with the solenoids and gates. The base of the transistor is connected to the collector of a second transistor which is normally non-conductive. A pulse generator is triggered from the distributer used for controlling the gates, as before, but in this arrangement the output of the pulse generator is differentiated and applied to the base of the second transistor. The trailing edge of a pulse renders the second transistor conductive and this in turn renders the first transistor non-conductive, to block current through the selected solenoid. The arrangement shown in Fig. 3 operates from the ignition distributer. A pulse supplied to a sparking plug S triggers gate G and at the same time a pulse is fed through a diode to transistor TR4 to trigger the pulse generator which is connected in series with the injector solenoids (not shown) and gates G. Each sparking plug actuates the injector for the cylinder displaced by 180‹ of the engine cycle.