JPS58185951A - Fuel injection controlling method and device thereof - Google Patents

Abstract

PURPOSE:To aim at the simplification of a control unit, by converting the fuel feed quantity found according to the operating conditions of an engine into a fuel injection hour range, while outputting it as plural injection signals different in the injection time or injection hour range by one timer. CONSTITUTION:When a start signal S1 is outputted to the specified fuel injection valve, for example, 11a from a MPU 7, this signal is impressed on an FF 126a of a timer control circuit 12 and thereby the fuel injection valve 11a is operated through a driving circuit 10a. On the other hand, a hour-time conversion circuit 121 calculates a valve-open expected time t1 (=t0+T) from a start signal impressed time t0 and a valve-open hour T, and sets the time t1 to a register 122a. Next, a selection circuit 123 selects the earliest valve-open time ti upon comparison of values of each of registers 122a-122d and then outputs it to a comparison circuit 124. The comparison circuit 124 compares the value of a timer 9 with the time ti and, when both are congruous, transmits the signal to the FF 126a via a distribution circuit 125, thus stopping the valve-open signal.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fuel injection control method and apparatus for controlling fuel injection of an internal combustion engine.

Conventionally, this type of device and 1. There was one shown in Figure 1.

In this Figure 1, 1 is a crank angle sensor, 2 is an intake air amount center, 3Fi water temperature sensor, 4 is an intake air temperature sensor,
5Vi battery voltage, 6 is a throttle position sensor, the symbols of each of the above sensors are sent to a microprocessor 7, and this micro 10 setter 7 calculates the fuel supply amount from the signals of these sensors.

8 is a memory in which calculation programs and data are stored;
9a and 9b are timers that convert the fuel supply amount calculated by the microprocessor 7 into a fuel injection time width signal. The output of the timer 9a passes through drive circuits 10a and 10b to the fuel injection valves 11b, respectively.

11a. drive circuit 10a,
lOb is for current amplifying the fuel injection time width signal, and is opened during the fuel injection time width of the fuel injection valves 11a and 11bii to supply fuel corresponding to this fuel injection time width to the internal combustion engine.

Similarly, the output of timer 9b is sent to drive circuit 10c.

The fuel is sent to fuel injection valves 11d and 11c via 10d. The drive circuits 10c and 10d are for current amplifying the fuel injection time width signal, and are for driving the fuel injection valves 11c and 10d.
The lid is opened during the fuel injection time width and supplies fuel corresponding to this fuel injection time width to the internal combustion engine.

Next, the operation will be explained. The microprocessor 7 reads the internal combustion engine operating information obtained from the crank angle sensor 1, intake air amount sensor 2, water temperature sensor 3, intake air temperature sensor 4, battery voltage 5, and throttle position sensor 6 according to a program defined in the memory 8. The amount of fuel to be supplied to the engine is calculated based on the engine speed parameter, and the amount of fuel supplied as a result of this calculation is converted into a fuel injection time, and this time width is alternately set to the timer 9a or 9b.

Next, the output of the timer 9a or 9b drives the output drive circuit 10a, 10bt or 10c, 10d to control the fuel injection valves 11a, llb or ll for the above fuel injection time.
Open valves c and lid. FIG. 2 is a timing chart of the same, in which "■" indicates the crank angle sensor, ([F]), (O indicates the output waveform of the timer 9a, and D and E indicate the output waveform of the timer 9b.

Since the conventional fuel supply control device is configured as described above, the number of opening timings of the fuel injection valves 11a and 11bllie and lld is equal to the number of valve opening timings of the fuel injection valves 11a and 11bllie and lld (for example, in the above example, the number of valve opening timings of the fuel injection valves 11a and llb and llc and lid valve opening timing), a timer must be provided, which is expensive.

In the conventional example, the fuel injection valves 11a to 11d have two groups 1, but if all of the fuel injection valves 11a to lid have different timings, or if there are many fuel injection valves and all of them have different timings, or if the fuel injection valves are opened at different times, If the valve times are different from each other, a corresponding number of timers are required, which has the drawback of increasing the size of the device and making it expensive.

This invention was made to eliminate the above-mentioned conventional drawbacks, and an object of the present invention is to provide an inexpensive fuel injection control method and device by generating multiple timings or time widths using one timer. shall be.

Embodiments of the fuel injection control method and apparatus of the present invention will be described below with reference to the drawings. FIG. 3 is a block diagram showing the configuration of one embodiment. In this FIG. 3, a crank angle sensor 1, an intake air amount sensor 2, a water temperature sensor 3, an intake air temperature sensor 4, a battery voltage 5, a throttle 4 6, microprocessor 7, memory 8, drive circuit 1
0a to 10d1 The part of the fuel injection valve 11a-1id is the first
As shown in the figure, one timer 9 is used, and the output of this timer 9 and the output of the microprocessor 7 are sent to a timer control circuit 12. This timer control circuit 1
The output of No. 2 is outputted to drive circuits 10a to 10d.

Details of the timer control circuit 12 are shown in FIG. In this FIG. 4, 121 is a time-to-time conversion circuit, 122a to 12
2d is a register for storing the valve closing time; the output of the time conversion circuit 121 is sent to registers 122a to 122d, and the outputs of these registers 122a to 122d are output to the selection circuit 123. This selection circuit 1
23 selects the one with the earlier valve closing time and transfers it to the comparison circuit 124.

The output of the selection circuit 123 and the output of the timer 9 are sent to a comparison circuit 124. The timer 9 is the timer shown in FIG. 3, and always counts with a constant clock. Further, the comparison circuit 124 includes registers 123a to 12
When the valve opening time 3d and the value of the timer 9 match, a match signal is output to the distribution circuit 125 and the selection circuit 123. This distribution circuit 125 includes flip-flop circuits (hereinafter referred to as FF) 126a to 126a to output matching signals.
126d. F F 126
A to 126d output a predetermined signal after the start signal is applied until the match signal is applied.

Note that T in FIG. 4 is the opening time of the fuel injection valves 11a=11d corresponding to the fuel supply amount, which is input from the microprocessor 7 in FIG. ~S4 is transferred from the microprocessor 7 to the storage register 122a=122d, and is also transferred to the FFs 126a to 126d. Output R-P from FF126a -126d
4 is adapted to be transferred to the drive circuits 10a to lOd. Note that (4) in FIG. 5 is the output of the crank angle sensor 1, [
F]) to [F]) are the output waveforms of the timer 12, and ω
) is the input of the drive circuit 10a, C) is the input of the drive circuit 10b, ■ is the input of the drive circuit 10c, and @ is the input waveform of the drive circuit 10d.

Next, the operation of the fuel injection control method and apparatus of the present invention configured as described above will be explained.

When the microprocessor 7 outputs the opening time T of the fuel injector corresponding to the amount of supplied fuel and the start signal S1 for a predetermined fuel injector, for example, lla, the start signal S
1 is applied to the FF 126a, and the fuel injection valve 11a connected to it via the drive circuit 10a is opened to start fuel injection.

On the other hand, in the time-to-time conversion, the scheduled valve opening time L+=Lo +T is calculated from the start signal application time 1o and the valve opening time T, and is set in the storage register 122a. Next, the selection circuit 123 compares the values of the storage registers 122a to 123d, selects the earliest valve closing time ti, and selects the earliest valve closing time ti,
Output to 4.

Next, the comparator circuit 124 constantly compares the value of the timer 9 and the valve closing time ti from the storage register, and when it detects a match between the two, it outputs a match (H< sign) to the distribution circuit 125. li'F1 corresponding to valve time ti
A matching key signal is output to 26a. FF that received a match signal
126a stops the valve opening signal output in response to the start signal.

As a result, a signal corresponding to the valve opening time T is outputted from Ii'F126a to 126d. That is, by using one timer 9, a plurality of pulses of arbitrary duration can be generated at arbitrary times.

Further, in the above embodiment, the control of the fuel injection valves 11a to 11a to lid has been described, but similar effects can be obtained if the fuel injection valves are driven by pulse drive or time width control.

Furthermore, in the embodiment described above, the timer control circuit 12 can also be implemented by software using a microprocessor to achieve the same effects as in the embodiment described above.

As described above, according to the fuel injection control method and device of the present invention, since a plurality of arbitrary time widths and sols can be output using one timer output, the device can be made inexpensive, and , which has the effect of obtaining high precision.

Further, if the above device is realized by software, a greater effect can be obtained.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of a conventional fuel injection control device, FIGS. A block diagram of the injection control method and device, FIG.
5A to 5G are timing charts of the fuel injection control method and apparatus shown in FIG. 3. FIGS. 1... Crank angle sensor, 2... Intake air amount sensor, 3... Water temperature sensor, 4... Intake air temperature sensor, 5...
-Battery voltage, 6・Throttle position sensor, 7
--Micro processor, 8--memory, 9--timer, 10 a to 10 d-drive circuit, l1a-11
d-Fuel injection valve, 12... timer control circuit, 122a
~122d...Storage register, 123--Selection circuit, 124...Comparison circuit, 125...-Distribution circuit, 12
6a to 126d... Fritzno flop circuit. The same reference numerals in the figures indicate the same or corresponding parts. Agent Shin Kuzuno −

Claims (2)

[Claims] (1) Calculate the fuel supply amount according to a predetermined program based on the signal representing the operating state of the internal combustion engine, convert the fuel supply amount based on the calculation result into a sweetfish injection time width, and use one time counting timer. A fuel injection control method characterized by outputting a plurality of injection signals having different fuel injection time widths (1-1) and supplying fuel to the engine according to the injection signals. (2) A timer that divides the time when multiple fuel injection times or injection signals with different injection time widths are generated at any time and the operating state of the internal combustion engine 'f: predetermined based on the signal that represents Means for calculating the fuel supply amount in order to adjust the fuel flow rate to a predetermined air-fuel ratio according to a program, and converting the fuel supply amount as a result of this calculation into a fuel injection time width using the timer; A fuel injection control device comprising means for injecting fuel in response to a signal.