| 摘要 |
1470961 Fluidic control circuits; regulating IC engine fuel injection LUCAS ELECTRICAL Ltd 3 April 1974 17610/73 and 55116/73 Headings F1B and F1P [Also in Division G3] The fuel supply to an internal combustion engine is controlled in accordance with the frequency produced by a vortex whistle placed in the inlet manifold to measure the air-flow rate. In the arrangement shown in Fig. 1 the acoustic signal from vortex whistle 30 is used through fluid connection 32 to operate the fluidic elements 34, 40 and 45 to produce on the output line 48 a pressure pulse signal causing fuel to be passed through line 57 to injector 58 for a time determined by delay line 46. At the end of the delay period bi-stable 45 relapses and stops the supply of fuel to injector 58. The injector thus passes equal length pulses of fuel at a rate dependent on the frequency of the acoustic signal from the vortex whistle. The analogue electrical circuit to provide a similar control is shown in Fig. 6 and uses signals from the distributor 98 to reset the integrators A1 and A5 so that the voltage developed across A1 is representative of the speed of the engine and is applied to integrator A5 through resistor R3. The acoustic signal from a microphone associated with the vortex whistle causes a voltage to be developed by integrator A3 which is proportional to the frequency of the acoustic signal. This voltage also is applied to integrator A5 through resistor R4 for a time determined by the period of monostable circuit 102. Transistor Tl conducts for a period dependent on the voltage on capacitor C5 and operates the injector 91 accordingly. A circuit having a similar characteristic but using digital techniques is described Fig. 7 (not shown). In the form of Fig. 4 (not shown), the injector is an input modulator in which a flow of high pressure air normally blocks the injection being diverted intermittently in accordance with the vortex whistle frequency to allow fuel to be sprayed into the induction air. |
