GB1311479A - Petrol injection systems for internal combustion engines - Google Patents

Abstract

1311479 Selective signalling JOSEPH LUCAS (INDUSTRIES) Ltd 23 July 1970 [17 Sept 1969] 45786/69 Heading G4H [Also in Division F1B A fuel injection system includes a memory device 12 on which are stored information sets 13 each containing a number of coded signals representing different fuel quantities, a storage device in which is stored a control signal determining the fuel quantity delivered, the control signal being obtained from the memory device, means responsive to one significant parameter for determining from which set the signal fed from the memory device to the storage device is obtained and means sensitive to another significant parameter for determining which coded signal from the chosen set is fed from the memory device to the storage device. The parameters may be engine speed and throttle opening or manifold depression. The enginedriven device 12 stores twelve sets 13 each containing ten coded signals in the form of eightbit rows extending across the drum to be read by head 14. The first seven bits define delivered fuel quantity and the eighth bit provides a contrcl pulse fed to counter 17. On receipt of an input pulse from a bi-stable circuit 20 a static register 15 registers the seven bits being read and feeds this information to a digital to analogue converter 21 which provides a continuous output analogue signal to a fuel control device which meters the injected fuel. A coincidence detector 23 which operates only when a datum signal is read triggers a timing pulse generator 16 which produces an output pulse of fixed duration, the start of which resets counter 17 to zero. The counter 17 maintains a count corresponding to the row in a set being read and its signal is fed to a comparator 18 which also receives a signal from a throttle angle encoder 19. When the two signals are equal a signal is fed to the bi-stable 20 (not being permitted to affect it until the pulse from generator 16 has ended) which triggers the register 15. In a modification the throttle angle determines which set is selected and the engine speed determines which row in the set is utilized.