Vorrichtung zum Schutz eines Triebwerks vor Überdrehzahlen

摘要

The fuel supply to a turbojet engine is controlled by a main metering valve 7, which has an adjustable valve device 18, whose pressure difference between inlet and outlet is maintained constant by a differential pressure controller 5. A safety feedback valve 12, on speeding of the engine, feeds fuel back to a fuel tank 1 before it enters the main metering valve, independently of the main metering valve, in such a way that a maximum permissible engine speed is maintained constant. If a malfunction of the main metering valve is detected by a computer 15, at least some of the functions of the main metering valve 7 are imposed by the computer on the safety feedback valve so as to retain a degree of control over the engine. Details of input signals to a PID controller (21)(Fig. 2) of the computer 15, are disclosed.