JPS6013946A - Fuel controlling method for engine - Google Patents

Abstract

PURPOSE:To simplify the structure of detectors and the circuitry and to control fuel exactly, by determining the sampling period of signals representing the pressure in an intake pipe by use of an electric signal representing the fuel supply timing. CONSTITUTION:Operation of a fuel injection valve 3 is controlled by affording the output signals of a crank position detector 7 and a detector 6 for detecting the pressure in an intake pipe and applying data processing and correction to the same. The sampling period Ts is determined by calculating the calculation period T from the periods T1-T3 of the pulses produced from the crank position detector 7 and dividing the calculation period T equally into prescribed parts. The fuel flow rate is controlled by detecting the pressure in an intake pipe from the sampling period Ts and calculating the mean value of the same. Thus, it is enabled to simplify the structure of detectors and the circuitry and to control fuel exactly.

Description

[Detailed description of the invention]

The present invention provides a method for detecting engine conditions and applying electrical processing to control fuel supplied to the engine. ! l″
It is something that is fru. In engines, especially automobile gasoline engines, the engine status is detected and electrically processed to reduce fuel consumption and exhaust gas. Techniques for controlling either or both air flows are well known. The elements detected as engine status are intake air amount and intake air temperature. Suction pipe pressure, throttle valve opening, engine speed. Engine temperature, crank position, exhaust gas components. This includes the operation of the exhaust gas recirculation system, but when inputting the intake pipe pressure as an electrical signal to an electronic control unit for air-fuel ratio control, the intake pipe pressure fluctuates in synchronization with the engine speed. , crank position or ignition timing, and inputs the electrical signal to the control unit to determine the sampling period of the suction pipe pressure signal. Therefore, an electrical signal for determining the sampling period is input to the control unit separately from the electrical signal for determining the fuel supply timing by the crank position or ignition timing detector.

[It is necessary to configure the circuit so that the +g signal is not input erroneously to each logic circuit block.
Since a current of 7'C is generated from several to hundreds of pulses as an electrical signal for determining the sampling period, the structure of the crank position detector 2 and the flame timing detector becomes complicated. . The present invention solves these problems and simplifies the circuit and configuration of the crank position or ignition timing detector by determining the sampling period of the intake pipe pressure signal using the electrical signal of the fuel supply timing. A method is provided for controlling fuel by inputting an appropriate TC suction pipe pressure signal into a control circuit. That is, the fuel control method for an engine according to the present invention includes:
Output signals for fuel flow control and fuel supply timing determination from the suction pipe pressure detector and crank position or ignition timing detector are input to an electronic control unit and electrically processed to perform fuel control. Alternatively, the calculation period is determined by correcting the previous period of the output signal from the ignition timing detector by the difference between one or several previous periods, and this calculation period is divided into equal parts of a preset number and then sampled. It is characterized by determining the cycle and controlling the fuel flow rate. Next, embodiments of the present invention will be described based on the drawings. In FIG. 1, a fuel injection valve 3 and a throttle valve 4 are installed in an intake passage 2 that supplies air-fuel mixture to -f carrot l, a suction pipe pressure detector 6 is installed in an intake pipe 5, and an engine 1 A crank position detector 7 is provided at. Suction pipe pressure detection! ; S6 continuously detects the suction pipe pressure that fluctuates as in the second latch IA in synchronization with the engine rotation speed, and sends a continuous electric signal to the electronic control unit 8.
input to the A-D converter 9. The crank position detector 7 emits a pulse as shown in FIG.
ll Data processing and necessary corrections are performed based on the suction pipe pressure signal inputted to the night circuit (microprocessor unit) 10 and sent from the A-D converter 9 to the control circuit O and the above-mentioned crank position signal. A necessary motion signal is sent to the injection valve 3 to control the structure and timing of fuel supply. The fluctuations in the suction pipe pressure shown in FIGS. 2A and 2B are synchronized with the crank position signal, and the pulses P and P2 of the crank position signal vary depending on the engine speed. P, P, period T work, T2. T3 changes. According to the present invention, when the pulse generator is input to the control circuit Ofc, the time from the previous pulse P2 to the current pulse P1, that is, the period T1 can be determined. Also, for example, the previous two times a T2. T3 is stored, and the difference between them is Δ,=T2−T. Δ2=T3”r2 is calculated. If Δ□=Δ2=0, engine 1 is running at a constant speed, and Δ0.Δ2〉0
If Δ□, Δ2〈0, then deceleration operation is occurring, so using these functions f(Δ, Δ2) as a correction factor, Tl1C1J! 'l-E D until next pulse generation
It is calculated by the period T'8-T=T+f(Δ0.Δ2). This calculation period T is equally divided into a predetermined number N to determine a sampling period T,=high. These calculations are performed by the control circuit 10, and the sampling signal S is obtained at intervals corresponding to the sampling period T. S engineering...
. . . SN (FIG. 3C) is sent to the A/D converter 9, the suction pipe pressure is detected for each sampling signal, and the average value is calculated. This average value is connected to the suction pipe pressure signal and the control circuit 1
0 and performs basic control of the fuel supply amount. That is, when the crank position detector 87 emits a pulse, the next cycle is predicted based on the calculation cycle T to determine the fuel flow rate, which is the 9th pulse T. The actual period T of the calculation period T predicted when is input to the control circuit 10. Since we know that, the 9th calculation period is this period T
. Δ. =Tyo-To, Δ, =T2-T function f(Δ
. , Δ1) as correction factors. The same effect can be achieved even if the fuel supply timing is determined by detecting the engine ignition timing instead of the crank position, and the function added as a correction factor is not limited to three times, but is based on the difference in the period that has been detected an appropriate number of times before. can be used. Furthermore. It is the same as before that the fuel flow rate is further corrected according to the appropriate factors of the engine condition mentioned at the beginning. As described above, according to the present invention, calculations are performed to correct the previous cycle of the output signal consisting of pulses from the crank position detector or the ignition timing detector using the difference in cycles, and calculate the next cycle. The calculation period is divided into a preset number of equal parts to determine the sampling period.
The fuel flow rate is controlled by detecting the suction pipe pressure based on this sampling period and calculating the average value, which simplifies the configuration of one circuit and the detector.Furthermore, the difference in period allows the engine to maintain constant speed, acceleration, Since it determines deceleration and predicts the cycle, appropriate fuel control can be performed.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the invention. FIG. 2 is a waveform diagram of electrical signals. 1...Engine, 2...Intake path, 3.
・Group・Fuel injection valve, 5...Suction pipe, 6...Suction pipe pressure detector, 7...Front position detector, 8...Control unit.

Claims (1)

[Claims] Output signals for fuel flow control and fuel supply timing determination from the suction pipe pressure detector and crank position or ignition timing detector are input to an electronic control unit and electrically processed to perform fuel control. Alternatively, the sampling period is determined by correcting the previous period of the electrical signal from the ignition timing detector by the difference between one to several previous periods, dividing the calculation period into a preset number of times, and determining the fuel flow rate. A fuel control method for an engine characterized by controlling.