GB609309A - Improvements in and relating to systems of and apparatus for detecting and regulating combustion conditions in an internal combustion engine - Google Patents

Abstract

609,309. Automatic control systems for internal-combustion engines. SPERRY GYROSCOPE CO., Inc. March 22, 1945, No. 7314. Convention date, March 22, 1944. [Class 38 (iv)] [Also in Groups XXVII, XXXVIII and XL (c)] In a system for controlling and indicating the presence of detonation in an internal - combustion engine, signals representative of combustion conditions are obtained from a pick-up on the engine and amplified to a common level. Signals representative of detonation being separated on an amplitude basis and used to actuate indicating and mixture controlling means. Figs. 1 and 2 show an arrangement in which signals from a pick-up 30 are applied to amplifier A, the output of which is fed to an A.G.C. circuit 65, Fig. 2, which enables a constant mean output to be obtained from A, diode 62 being provided to reduce the inverse voltage and hence the leakage across diode 57, by shorting the amplifier output when 57 is not conductive. Detonation signals are separated from combustion signals on an amplitude basis by means of a limiter, comprising discharge tube 63 in series with resistor 61, which also serves to maintain the mean amplitude of the A.G.C. voltage constant. Impulses corresponding to detonation appearing across resistor 61 are applied to a prolonging amplifier which holds relay 73 for several seconds on receiving an impulse. If the "manual/automatic switch 90, 93 is set to automatic, closure of relay 73 operates two-way relay 97 which in turn operates motor 42, so that mixture is rapidly enriched by means of gears 44, 45, Fig. 1, and mixture control 14, until limit switch 100, Fig. 2, is operated. When relay 73 opens, relay 97 is no longer energized so that its contacts move back connecting the motor to the supply in such a manner that it slowly weakens the mixture, until detonation occurs again, or until limit switch 99 is operated. Manual mixture control is effected by means of lever 16, also the control may be motor driven to either of the limiting positions by means of switches 91 and 92 provided switch 90 is set to " manual." Detonation signals are applied through a suitable detecting and smoothing network to a meter 87 and a recorder 88, to give a reading of the amount of detonation occurring. Visual indication of detonation is given by discharge tube 89, which is associated with detonation counter 105. Setting switch 93 to " automatic " energizes electromagnetic clutch 46, which couples motor 42 to shaft 23.