Patent GB-496789-A (GB)
Title: Improvements in and relating to means for indicating or controlling the content of fuel and air mixture for internal combustion engines
IPC: F02D9/00
Filed: 1938-03-01
Abstract: 496,789. Automatic control systems. MUSELIER, B. G. M. March 1, 1938, No. 6475. Convention date, March 1, 1937. [Class 38 (iv)] [Also in Group XXVII] Proportioning mixtures.-A device for controlling the quality of a fuel and air mixture for internal - combustion engines comprises two movable members, one of which is periodically actuated to take up a position which is a function of the quantity of fuel flowing to the engine and is then brought back to its initial position, while the other member is moved in accordance with the temperature and pressure of mixture, so that at each periodical displacement of the first member, the relative position of the two members effects a correction of the quality of the mixture. The second member may also be subjected to changes in atmospheric pressure, or to the engine torque ; or the engine torque or the calorific value of the fuel may be made to influence means controlling the period between the actuations of the first element. The correction may be effected by adjustment of a throttle valve in a secondary air inlet, or of the position of the fuel jet in the Venturi of the carburetter either through electric relays or fluid-actuated means. Fig. 4 shows diagrammatically one form of device in which a cam 16 driven by the engine actuates, after a certain number of revolutions of the engine, a lever 97 so as to close a contact 15, which energizes a magnet 10 causing movement of the first above-mentioned member or arm 14 towards the second member or arm 21, these members having contacts 17 ... 20 which co-operate to effect control. Fig. 1 shows means for making the movement of the arm 14 dependent on the quantity of fuel flowing to the engine. A fuel-flow meter 92 drives a gear-wheel 1, which, when the magnet 10 is periodically energized, is coupled to a second wheel 3 by means of a pinion 5 carried by a lever 6 under the influence of the magnet, the shaft of the wheel 3 also carrying the arm 14. The arm 21 is mounted on a shaft 22 coaxial with the wheel 3 and is actuated by a pinion 51, Fig. 3, and sector 50 adjustably connected at 44 to a rod 37, also adjustably connected to a lever 32, the ends of which are acted on by capsules 23, 24, the former being under the influence of the pressure of the mixture in the suction pipe 26 of the engine by a connection 29, and the latter under the influence of the temperature of the mixture by means of a thermostatic capsule 24 and pipe 27. Fig. 11 shows a device for correcting the mixture through electric relays 58, 59 and a motor 60 actuating the air or fuel controls, or both. When the mixture is too poor and none of the contacts 17 ... 20 engage, the motor receives current through contacts 62, 66 and winding 67, so that it rotates in the direction to increase the fuel, cr decrease the air supply. A correct mixture brings the contacts 18, 19 into action and, through relay 58, opens the contacts 62, 66, so that no current is supplied to the motor. A too-rich mixture, however, closes all the contacts 17 ... 20 and brings both relays 58, 59 into action to close contacts 62, 63 and 64, 65, so that the motor receives current through the other winding 61 and rotates in the opposite direction to increase the air, or reduce the fuel supply. The holder 68 of the contacts 15 may be adjusted by hand, or automatically according to the engine torque, to vary the number of revolutions occurring between the periodic actuation of the device.