Patent GB-488072-A (GB)
Title: Improvements in or relating to control apparatus for internal combustion engines
IPC: G05D13/00
Filed: 1937-10-04
Abstract: 488,072. Fluid - pressure servomotor - control systems. SULZER FRERES SOC. ANON. Oct. 4, 1937, No. 26838. Convention date, Nov. 7, 1936. [Class 135] An internal-combustion engine to which air is supplied by a supercharger and from which power is transmitted through transmission apparatus in which the torque ratio between the input and output shafts may be varied is controlled by a speed responsive governor and by a member sensitive to supercharging pressure. The arrangement is such that the supercharging pressure is prevented from rising above a predetermined value and that over a part of the range of supercharging pressures the load is controlled both by speed and by the supercharging pressure. In the form shown in Fig. 2, the engine 1 drives a generator 2, the field of which is adjusted by a rheostat 4 operated by a power piston 3. This piston is under the control of a valve device comprising an inner part 8 coupled to a speed governor 5 which also controls the fuel pump 7 and an outer sleeve 21 connected by a lever 20, rod 19 and elastic coupling 23 to an aneroid capsule 16 housed in a chamber 15 connected by a pipe 14 with the engine intake manifold 12. The aneroid capsule also actuates the control valve 17 of a power piston 24 connected by a bell-crank lever and link 25 to a valve 26 controlling the connection between the exhaust manifold and atmosphere. As the supercharging pressure rises the collapse of the capsule 16 first operates the sleeve valve 21 to increase the load in the engine. At a certain point a sleeve 18 on the rod 19 engages a fixed stop 22 thus preventing any further movement of the control valve 21 and setting an upper limit to the load. Subsequent increases of supercharging pressure cause the capsule to actuate the control valve 17 and so operate the piston 24 in the direction to open the valve 26 and thus reduce the quantity of exhaust gases delivered to the turbine 10 driving the supercharger 11. In the form shown in Fig. 3, the servomotor operating the field rheostat is controlled by the speed governor alone, which governor is coupled by an elastic coupling 34 with the fuel pump regulator. The capsule is connected by a floating lever 27 to a control valve 28 and a power piston 30 connected to a lever 31 adapted to act as a stop for the fuel pump regulator. The lever 31 has a lostmotion connection through a lever and linkage system 39 with a relief valve 40 on the induction pipe adapted when open to reduce the supercharging pressure. When the lever 31 has taken up the lost-motion the end 41 of the floating lever engages a fixed stop so putting it out of action as a floating lever. The lever and linkage system 39 may be arranged to operate a throttle valve in the supercharger induction pipe in place of the relief valve 40, or may alter the position of guide blades, rotor blades or nozzles of the exhaust turbine or the blades of the supercharger fan. Alternatively, cams of variable shape on a longitudinal cam-shaft may vary the charges supplied to the engine and so vary the quantity of exhaust gases supplied to the supercharger turbine.