| 摘要 |
PURPOSE:To improve air-fuel ratio control precision and to widen the regulation range of a combustion amount, by constituting a device such that control is effected by the use of a differential pressure sensor so that the upper stream pressure of an air throttle is normally kept equal. CONSTITUTION:Provided that a burner 15 for combustion burns a given type of gas in a normal manner and if, with this, a change is produced so that the burner 15 for combustion is increased in a combustion amount, an air amount regulating means 5 is operated so as to increase an air amount. Thus, a differential pressure force, based on a pressure difference DELTAP=PA-PG>O between an upper stream pressure PA of a variable primary air throttle 8 and an upper stream pressure PG of a regulation type nozzle 3, is produced at a differential pressure sensor 11. A differential pressure output signal therefrom is processed by an electric circuit 12 to regulate a gas amount regulating means 2 so that a gap amount is increased and to effect control making PA=PG, i.e., a pressure difference is brought to zero. If the differential pressure sensor 11 including an electric system has no error, an air-fuel ratio is kept constant even if a combustion amount is regulated. |
