JPS62347B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention detects the intake air amount of an internal combustion engine or a parameter equivalent thereto, uses a plurality of electromagnetic injection valves, and drives the injection valves with phases shifted from each other to improve internal combustion. The present invention relates to a fuel control device for an internal combustion engine that controls the amount of fuel supplied to the engine.

For example, fuel control of an internal combustion engine is performed by detecting the intake air amount of the internal combustion engine using Karman vortices, and using this detection output to control the electromagnetic injection valve arranged upstream of the throttle valve provided in the intake passage of the internal combustion engine. This is to control the amount of fuel supplied to the internal combustion engine.

That is, when a columnar object is inserted into a flowing fluid, vortices are generated alternately on both sides of the object, and the fluid flows downstream as a vortex train. This vortex is called a Karman vortex and is already a well-known phenomenon. A vortex generating device for a flow meter that utilizes this Karman vortex and a vortex detection method are described in detail in Japanese Patent Publication No. 13428/1983.

When a Karman vortex generating device is provided in an air intake passage of an internal combustion engine to detect the intake air amount of the internal combustion engine, a Karman vortex is generated in proportion to the intake air amount. Therefore, if a pulse generator that generates a pulse of a constant width is driven in synchronization with the generation of this Karman vortex, and fuel is supplied to the internal combustion engine only for the period of this pulse width, the above-mentioned pulse generator Fuel is supplied to the internal combustion engine in proportion to the output frequency. In other words, fuel can be supplied to the internal combustion engine at a constant rate with respect to the intake air amount.

Here, an electromagnetic injection valve is used to supply fuel,
Further, when an electromagnetic injection valve is arranged at a gathering part of the intake pipe of the internal combustion engine, it is necessary to provide a plurality of electromagnetic injection valves due to the operating time of the electromagnetic injection valve and fuel atomization.

For example, when two electromagnetic injection valves are provided, fuel can be supplied to the internal combustion engine more smoothly if the electromagnetic injection valves are driven intermittently with different phases.

In this case, it may be possible to control the electromagnetic injection valves by providing a timer for controlling the valve opening time for each of the two electromagnetic injection valves, but this timer is relatively large-scale. Since a detailed circuit configuration is required, the control device becomes complicated and expensive.

This invention has been made to eliminate the above-mentioned conventional drawbacks, and includes a flip-flop circuit (hereinafter referred to as
This FF is set by the output of the Karman vortex generator, the set time is detected by a timer, the opening time of the electromagnetic injection valve is added to this time, and the FF is set by the output of the Karman vortex generator. The circuit can be simplified by calculating the time to reset the FF and resetting the FF from time to time using the above-mentioned timer.The reset time of multiple FF can be controlled by one timer, thereby simplifying the circuit. An object of the present invention is to provide a fuel injection device for an internal combustion engine.

Embodiments of the fuel injection device for an internal combustion engine according to the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of one embodiment.

In FIG. 1, numeral 1 is an outer box of the vortex generator through which air taken into the internal combustion engine 3 passes, and numeral 11 is a vortex generator.

Further, 2 is a vortex detection device. The vortex detection device 2 is driven by an oscillation circuit (not shown) built into the device of the present invention, and drives an ultrasonic transmitter 21 to generate ultrasonic waves. The ultrasonic transmitter 21 is attached to the outer box 1 of the vortex generator.

The ultrasonic waves generated by the ultrasonic transmitter 21 are frequency modulated each time a vortex is generated by the vortex generator 11 and reach the ultrasonic receiver 22 . An ultrasonic receiver 22 is also attached to the vortex detection device 2 . The output of this ultrasonic receiver 22 is sent to the vortex detection device 2, which demodulates the change in the ultrasonic frequency with a built-in FM signal demodulator (not shown), and sends the output to the downstream part of the vortex generator 11. It is designed to output a pulse with a frequency corresponding to the generation frequency of the generated Karman vortex.

Reference numeral 3 denotes an internal combustion engine used in a car, for example, and the air is sucked in through the vortex generator 11 and the intake pipe 35, and the fuel supply valve (electromagnetic injection valve) 31 disposed upstream of the slot valve 33. ，
It operates with fuel supplied from 32. The throttle valve 33 adjusts the amount of air taken into the internal combustion engine 3.

A fuel pump and a fuel pressure regulator (not shown) are connected to the fuel supply valves 31 and 32, so that the differential pressure between the pressure of the suction pipe 35 and the fuel pressure supplied to the fuel supply valves 31 and 32 is kept constant. ing.

The internal combustion engine 3 is provided with a water temperature sensor 34 that detects the temperature of its cooling water. This water temperature sensor 34
is like a thermistor whose resistance increases as the temperature decreases.

Further, 4 is a control device that drives the injection valves 31 and 32 in synchronization with the frequency output from the vortex detection device 2,
The pulse width for driving the electromagnetic injection valve is controlled according to the operating state of the internal combustion engine 3.

FIG. 2 is a block diagram showing the detailed configuration of this control device 4. As shown in FIG. In this FIG. 2, the output of the vortex detection device 2 is input to the FF42, and
The two outputs are inverted every time a pulse is output from the vortex detection device 2, and the phases of these two outputs are different from each other.

For example, when a pulse is output from the vortex detection device 2, this output changes from "H" level to "L" level on one side,
The other output changes from "L" level to "H" level. The output end of FF42 is connected to monostable multivibrators MM1 and MM2, and these monostable multivibrators MM1 and MM2 output a short pulse when the output of FF42 changes from "L" to "H" level. .

The output end of monostable multivibrator MM1 is
It is connected to the set input terminal S of FF51 and the load input terminal of register REG1, and the output of monostable multivibrator MM2 is connected to the set input terminal S of FF52 and the load input terminal of register REG2.

Registers REG1 and REG2 store the output of the adder ADD when a signal is applied to the load input terminal. The output terminal of register REG1 is comparator CMP1
The output end of the register REG2 is connected to the comparator CMP2. The other input terminal of each of the comparators CMP1 and CMP2 is connected to the output terminal of the timer 44.

Comparator CMP1 compares the output of register REG1 and the output of timer 44, and when they match, generates an output and resets FF51.

Comparator CMP2 compares the output of register REG2 and the output of timer 44, generates an output when they match, and resets FF52.

Adder ADD adds the output of register REG3 and the output of timer 44.

The driving time control device 41 determines the amount of fuel supplied to the internal combustion engine 3 based on the operating state of the internal combustion engine 3, and controls the electromagnetic injection valve 3 in accordance with this amount of fuel supplied.
A numerical value corresponding to the time for driving 1 and 32 is stored in the register REG3.

The drive time control device 41 converts the output of the vortex detection device 2 into a voltage using an F-V (frequency-voltage) converter, and further converts this voltage into a digital value using an AD (analog-digital) converter. The operating state of the internal combustion engine 3 is detected by similarly converting the output value of the thermistor 34 into a digital value and taking it in.

While the FFs 51 and 52 are set, they drive the fuel supply valves 31 and 32 to control their opening. The timer 44 is an up counter that counts the output of the oscillator 43 with an oscillation period t, and when it reaches the maximum count value, it starts counting up again from zero.

Next, the operation of the fuel injection system for an internal combustion engine of the present invention constructed as described above will be explained using the time chart shown in FIG. Assume that the driving time control device 41 stores a numerical value N corresponding to the opening time T of the fuel supply valves 31 and 32 in the register REG3. Here, N=T/t.

Now, at time t ₀ , the output of the vortex detection device 2 is FF42.
When the input to monostable multivibrator MM1 changes from "L" to "H" level, monostable multivibrator MM1 outputs a short pulse, sets FF51, and drives fuel supply valve 31. . Also, the value of the adder ADD at that time is stored in the register REG1.

At this time, if the value output by the timer 44 is M, the value (M+N) is stored in the register REG1. That is, the numerical value M output by the timer 44 corresponds to time t ₀ , and the numerical value N of the register REG3 corresponds to the valve opening time T, and these two are added by an adder (ADD) and stored in the register REG1. is (t ₀ +
T) is stored. Comparator CMP1 is timer 44
has counted M from time t ₁ , that is, after time (t ₀
+T) and resets FF51. That is, the fuel supply valve 31 is driven for a time T when the input of the monostable multivibrator MM1 changes from "L" to "H" level.

Similarly, the fuel supply valve 32 is also driven for the amount of time T after the input of the monostable multivibrator MM2 changes from the "L" level to the "H" level.

In this embodiment, there are two fuel supply valves, but
In the case of three or more counters, it can be configured with one counter in the same way.

Alternatively, the timer 44 may be a down counter and a subtracter may be provided to determine the time at which the FF is reset.

Note that the registers REG1, REG2, REG3 and the comparators CMP1, CMP2 can be configured relatively more easily than the timer 44.

In addition, if the drive time control device is configured with a microcomputer, register REG3, adder
ADD can use it in this microcomputer, and the control circuit becomes simpler.

Furthermore, in the above embodiment, the fuel is supplied to the internal combustion engine in synchronization with the Karman vortex generated in proportion to the intake air amount of the internal combustion engine, so that the fuel is supply can be quickly followed.

In addition, in the above embodiment, the injection valve is driven in synchronization with the Karman vortex, but if the injection valve is driven in synchronization with the rotation speed of the internal combustion engine and the opening time of the injection valve is controlled according to the amount of intake air. The present invention can also be applied to.

As is clear from the above description, according to the fuel injection device for an internal combustion engine of the present invention, at least one FF is provided corresponding to a plurality of fuel supply valves, and this FF is injected by the output of the Karman vortex generator. At the same time, the set time is detected by a timer, and the opening time of the fuel supply valve is added to this time.
By calculating the time to reset the FF and resetting the FF at this time using a timer, it is possible to control the opening times of multiple fuel supply valves with one counter means, and accurately control the amount of fuel supplied. The control circuit can be easily and inexpensively constructed.

Furthermore, since the opening time of the fuel supply valve is controlled and the number of injections is not controlled, the fuel injection valve does not require frequent opening and closing, and an inexpensive fuel injection valve that does not require high performance can be used.

Furthermore, the timer means can be used in addition to controlling the injection valve.
For example, it can be used to create timing for a fixed time period, and a single timer means can control a plurality of various times, further simplifying the circuit.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of the fuel injection device for an internal combustion engine according to the present invention, FIG. 2 is a block diagram showing the detailed configuration of the control device in the fuel injection device for the internal combustion engine, and FIG. is a time chart of the fuel injection device according to the present invention. DESCRIPTION OF SYMBOLS 1... Vortex generator, 2... Vortex detection device, 3... Internal combustion engine, 4... Control device, 21... Ultrasonic transmitter, 22... Ultrasonic receiver, 31, 32... Fuel supply valve , 33... Throttle valve, 34... Temperature sensor, 35... Suction pipe, 41... Driving time control device, 42, 51, 52... Flip-flop circuit, 43... Oscillator, 44... Timer,
REG1, REG2...Register, ADD...Adder, CMP1, CMP2...Comparator.

Claims (1)

[Claims] 1. A plurality of fuel supply valves using electromagnetic injectors that are driven intermittently to supply fuel to the internal combustion engine in a phase-shifted manner, and air that creates a mixture in the engine together with the fuel injected from the fuel supply valves. A vortex detection device that outputs a frequency pulse train for the Karman vortex generated in response to the flow rate, a drive time control device that sets the opening time of the fuel supply valve depending on the operating state of the internal combustion engine, a timer unit that counts the time, and Adding means for adding the valve time and the counted value of the timer means; a register for storing the added value by the adding means in synchronization with the output of the vortex detection device; and comparing the stored value of the register and the counted value of the timer means so that they match. At least one comparison means is provided corresponding to each of the plurality of fuel supply valves and is set by the output of the vortex detection device to drive the fuel supply valve open and to output an output when the comparison means A fuel injection system for an internal combustion engine comprising a flip-flop circuit that is reset by output to close a fuel supply valve.