Patent GB-1495405-A (GB)
Title: Internal combustion engines
IPC: F02D41/24
Filed: 1975-02-28
Abstract: 1495405 Stratified charge internal combustion engines NIPPON SOKEN Inc 28 Feb 1975 [1 March 1974 6 June 1974 16 July 1974] 8535/75 Heading F1B An I.C. engine has a cylinder 1 having a main combustion chamber 5, an intake port 13a with an intake valve 16, an intake passage 13, an auxiliary combustion chamber 8 with a sparking plug 9 and a fuel injection system comprising a nozzle 110 with an opening 110a directed into the intake passage 13 and means 100 arranged to supply fuel to the nozzle 110 once during a suction stroke of the engine and at least more time during a stroke of the engine other than the suction stroke, in each engine cycle. The auxiliary chamber 8 has two apertures 10, 11 separated by a wall 12. During suction, the valve 16 directs a stream of fuel from nozzle 110 over its upper surface into the aperture 10, suction through aperture 11 aiding the introduction of fuel to the chamber 8. Mechanical fuel injection control. Fig. 3 shows a shaft 133 rotated by gearing at ¢ engine crankshaft speed and a three dimensional cam 130 shifted longitudinally of the shaft 133 by a further cam-shaft 136 operated in tandem with a throttle valve 17. Fuel is supplied from a tank 140 by pump 129 to a piston pump chamber 121 and pumped from there to the nozzle 110 by means of a piston 123 reciprocated by the three-dimensional cam 130 in synchronism with crank-shaft rotation. The cam 130 has two opposed lobes so that two injections are made for each rotation of the shaft 133, one injection being synchronized with a suction stroke and another with a combustion stroke in a 4-stroke engine. The cam 130 adjusts the total fuel injected and the ratio of fuel quantities injected in each stroke according to throttle valve setting. Electronic fuel injection control. The injection nozzles 210 Fig. 8 may be solenoid actuated by pulses from a control system which incorporates the following sensors; 290 for detecting engine coolant temperature, 292 for detecting crank-shaft speed and 293 for detecting air-flow volume in the intake manifold 14. Signals from these sensors are processed to give a series of pulses which have a pulse length determined by the equation KQ(1 + K<SP>1</SP>)/N where K is a constant dependent on the air-fuel ratio of the mixture supplied by the engine, Q is the volume of air flowing to the cylinder in each engine cycle (derived from sensor 293), K<SP>1</SP> is a quantity dependent on engine coolant temperature (derived from sensor 290) and N is the engine rotational speed (from sensor 292), in a fourcylinder four-stroke engine with firing order "1, 3, 4, 2", four such pulses are formed per two rotations of the crank-shaft. This sequence of pulses is divided into two signals of alternate pulses. The first signal is applied to the injection valves of cylinders 1 and 4, thus injecting fuel on the induction stroke of cylinder 1 and the firing stroke of cylinder 4 and vice versa. The second signal is applied to cylinder 2 and 3 with a similar effect. In a modification electronic circuitry is provided to adjust the ratio quantity of fuel injected during suction stroke/quantity of fuel injected during combustion stroke, in accordance with engine operating conditions e.g. throttle setting, engine temperature.