GB511930A - Improvements in and connected with the regulation of super-charged internal combustion engines, particularly aircraft engines - Google Patents

Abstract

511,930. Fluid-pressure servomotor-control systems. DAIMLER-BENZ AKT.-GES. March 21. 1939, No. 8938. Convention date, March 24, 1938. [Class 135] [Also in Group XXVII] In supercharged engines, particularly of aircraft, wherein two working factors are positively varied by a manual control, one factor (e.g., changing pressure) being dependent on atmospheric pressure and also upon the other factor (e.g., speed) means are provided whereby, when the atmospheric pressure falls too low to maintain the first factor, the second factor is adjusted so as to restore the first to its desired value. The Figure shows a pilot's control lever 17 connected (a) to a capsule 21 which is subjected to the changing pressure of a blower 12 and controls a throttle 14 in the blower discharge by means of a servomotor 24, 27, and (b) to the sleeve 11 of a centrifugal governor 8 controlling the pitch of the propeller blades 4. Adjustment of the lever 17 from A to D displaces the capsule 21 to increase the blower pressure, and at the same time adjusts the sleeve 11 to increase the load on the governor and thereby the speed. When atmospheric pressure becomes decreased at altitudes, the changing pressure of the blower falls below the prescribed value, and to restore the changing pressure an aneroid 31 is provided which, under such conditions, contracts the toggle linkage 28, 29 so as to increase the speed of the engine and therefore also of the blower. When the lever 17 is in the idling position A, it contacts with a lever 18 connected to an idling throttle 15. At the position B, the lever 18 is prevented from moving farther by a stop 19, the throttle 15 being then fully open. When the lever 17 is moved beyond the fulloutput position D for starting, a further lever 40 is actuated to increase the fuel supply by means of a connection 42, 38 to the fuel pump 16. This pump is also under the control of a piston 36 acted on by the changing pressure. In a modification, the lever 17 is also connected to the aneroid 31 so as to displace it bodily; an adjustable arm may be introduced between the lever 17 and the aneroid. A relay may be provided between the linkage 28, 29 and the governor. Also cams may be provided between the control lever 17 and the connections to the blower and governor controls, so as to vary the relative adjustments of each.