JPS58192936A - Fuel injection device operable at start-up of internal-combustion engine - Google Patents

Abstract

PURPOSE:To allow the captioned device to inject a fuel immediately after start- up, by obtaining a fuel injection quantity merely from an engine temperature at starting-up of the engine. CONSTITUTION:At an early stage after starting-up, a fuel injection timing determining means 2 functions to read out a fuel injection timing signal Ts responsive to an engine temperature at this time from a memory 21 for carrying out computation for interpolation. A timing changing circuit 5 is adapted to produce a pulse output having a pulse interval responsive to the signal Ts which is outputted by the fuel injection timing determining means 2 at an early stage after starting-up. In this manner, a driver 6 is driven to cause a fuel injection valve 7 to inject a fuel. Since this arrangement does not depend on an engine speed to control at starting-up, a fuel can be injected from the time when the first engine pulse is generated.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a starting fuel injection device for an internal combustion engine.
In particular, the present invention relates to a precise starting fuel injection system for an internal combustion engine that determines and controls the amount of fuel supplied until the first engine pulse occurs during starting.

Conventionally, a fuel injection time signal is determined based on two or more parameters: engine speed and at least one engine parameter such as idle negative pressure and throttle valve opening. It is known to control the opening time of a fuel injection valve and control the fuel supply to an internal combustion engine based on b.

In such conventional technology, even if the engine is driven by a starter motor etc. at the time of starting, the engine rotation speed cannot be calculated if only the first (first) engine pulse is detected after the first #dJ. Therefore, the fuel injection time signal cannot be determined.

Only when the second engine pulse is detected and the time interval (period) between the first and second pulses is known, the engine speed can be calculated and the fuel injection time signal can be obtained.

Therefore, fuel injection cannot be supplied to the first (first) engine pulse after starting, and the starting performance of the engine is degraded accordingly.

SUMMARY OF THE INVENTION An object of the present invention is to provide a starting fuel injection device for an internal combustion engine that can improve the above-mentioned drawbacks and can inject fuel even for the first engine pulse after starting.

The present invention will be described in detail below with reference to the drawings. 1st
The figure is a block diagram of one embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes depth fuel injection time determining means, which stores a basic fuel injection time signal T1 using engine speed No. and intake negative pressure PB or throttle valve opening #th as parameters. memory 11, a first interpolation calculator 12 that performs an interpolation calculation of the basic fuel injection time signal T1 read from the Ti memory 11, and the output of the first interpolation calculator 12 is corrected based on atmospheric temperature, pressure, etc.;
It is composed of a correction calculator 13 that outputs a depth fuel injection signal Tio.

It is a fuel injection time signal determining means at the time of starting, and uses the engine temperature TI (at least one of the data representative of the engine temperature, such as engine oil temperature, water temperature, intake air temperature, etc.) as a parameter. The second interpolation calculator 22 includes a memory 21 that stores the fuel injection time signal Tg, and a second interpolation calculator 22 that performs interpolation calculations as necessary on the signals read from the first Ts memory.

3 is the JL's first (first) engine pulse detection means, and is a monomulti that generates a short pulse in response to the closing of the ignition switch (or starter switch, hereinafter simply referred to as the ignition switch) S. It is composed of a vibrator 31 and a flip flora f52 that is reset by the output of the mono-multivibrator 31 and set by the engine pulse.

Reference numeral 4 denotes a signal selection means, which includes a starting initial fuel injection time signal Tso from the second interpolation calculator 22 and a first amplifier Pr-to 41 which makes the available output of the flip-flop 32 human-powered.
, an inverter 42 supplied with the q output of the flip-flop 32, and an output of the inverter 42 and a correction calculator 1.
a second un-V date 43 in which the execution fuel injection time signal Tio from No. 3 is powered by two people;
45 and an ordate 44 that requires two people to output.

5 is the image number (
A time conversion circuit 6#-i is supplied with the output of the time conversion circuit 5 and converts the actual fuel injection time signal Tio'i or the initial fuel injection time signal T8o) into a pulse having a time width corresponding to the value thereof. This is a P type oiler that drives the fuel injection valve 7.

Next, referring to the Thai chart in Figure 2, '! ! &
The operation of the apparatus shown in FIG. 1 will be explained.

When the ignition switch S is turned on during operation,
A mono-multivibrator 31 generates a short-lasting pulse, which causes a flip-flop (hereinafter referred to as FF
) 32 is reset. the result,? F5
Since the output power of 2 becomes 1, the amplifier p)f-)41 is opened, and on the other hand, AND? - gate 43 is closed.

At this time, in the starting initial fuel injection time signal determining means 2, the fuel injection time signal TB corresponding to the engine temperature TI at that time is successively outputted from the memory 21, and interpolation calculations are performed as necessary to determine the engine temperature TBi. Accordingly, an appropriate starting initial fuel injection time signal Tso is output.

Therefore, FF52 is in reset state 1iltrC,
While the available output is 1, 4 signal selection means,
The starting initial fuel injection time signal Too is selectively outputted and supplied to the time conversion circuit 5.

Time conversion circuit 5Fi, the starting initial fuel injection time signal T
A pulse output with a width of 9 hours is generated in response to so, and the driver 6 is driven by this, the fuel injection valve 7 is opened, and a predetermined amount of fuel is injected and supplied.

When the engine rotates and a negative engine pulse is detected, the FF 32 is set and its possible output becomes zero.

As a result, An\r-)41ii is closed, and P-
45 is opened.

When the engine continues to rotate and two engine pulses are detected, the engine rotational speed is calculated and supplied to the T1 memory 11.

Therefore, the fuel injection time determining means reads out the basic fuel injection signal Tf, performs interpolation calculation, and performs an interpolation calculation using the engine rotational speed Me and the intake negative pressure PB or the throttle valve opening #th as parameters. Correction calculations and the like are performed, and an effective fuel injection signal Tio is output.

1st execution fuel injection signal 4! TioFi, signal selection means 4
The signal is supplied to the time conversion circuit 5 via the ANDr-) 43 and the OR'-t 44. Then, as described above, it is used to control the opening time of the fuel injection valve 7.

In the above description, the present invention will be described as a bar using unit logic elements.
Although an example implemented as a configuration has been described, the present invention can also be easily implemented using a microcomputer or the like.

Next, a procedure for implementing the process using a microcomputer or the like will be explained with reference to chart 70 in FIG. Note that the symbols in the flowchart have the same meanings as those in FIGS. 1 and 2.

When the procedure starts, the engine pulse counter is reset to 0 in step 81h, and it is determined in step s2 whether the ignition switch (or starter switch) is closed.

If the ignition switch is not closed, wait until it is closed, and if it is closed, proceed to step s5 and set the engine salt [T I, suction negative pressure PB, throttle valve opening -th, engine speed Null, etc. is read, and the process further advances to step 84.

Stella 7'B4 determines whether the count value of the engine pulse counter is 1 or greater.

At the beginning of startup, the count value is 0, so the determination at this step is not valid, and the procedure proceeds to step 85, where Ta is set using the engine ffi degree T as a parameter.
Take out the fuel injection time image Ts from memory.

The process then proceeds to step 86, where one interpolation calculation is executed as necessary, and the starting initial fuel injection time signal Tso is output at Stella fEJ7. Then, the process proceeds to step 812, which will be described later, to execute fuel injection, and then returns to step 82.

When the engine starts rotating, an engine pulse is detected soon, and the engine pulse counter value becomes one or more. Therefore, the judgment with Stella fB4 is now valid, and the procedure is from Stella fB4 to B8.
You will be able to proceed to

In step B8, the T1 memory is successively read out according to a known method. Then, in steps B9 and B10, interpolation calculations and correction calculations are performed as necessary, and in Stella f811, the output of the effective fuel injection time signal Tio is performed.

In step 812, the fuel injection time (ff number Ts) is determined.

Alternatively, the opening time control of the fuel injection valve is executed according to the timing. That is, fuel injection is supplied in synchronization with the engine pulse, and then 1,000 MM steps s
Return to 2.

As is clear from the above description, according to the present invention, it is possible to properly inject and supply fuel from the negative engine pulse when starting the engine, so that the starting performance of the engine can be improved. .

[Brief explanation of drawings]

%1 is a block diagram of one embodiment of the present invention, FIG. 2 is a time chart for explaining its operation, and FIG. 3 is a flow chart when the present invention is implemented by a microcomputer or the like. DESCRIPTION OF SYMBOLS 1... Execution fuel injection time determination means, 2... Starting initial fuel injection time signal determination means, 3... Engine pulse detection means, 4... Signal selection means, 5... Time conversion circuit, 6 ...12 fiber, 7... fuel injection valve, 11...
・T1 memory, 21...Tg memory, 31...Mono Multi Isolator Patent attorney Michihito Hiraki and 1 other person

Claims (1)

[Claims] (1) Executable fuel injection time determining means that outputs a fuel injection time signal based on at least one of engine parameters such as engine rotational speed, suction negative pressure, and throttle valve opening; and based on engine temperature. starting initial fuel injection time signal determining means for outputting a fuel injection time signal at the beginning of starting, and selecting an initial starting fuel injection time signal until the first engine pulse occurs at starting, the signal selection means for selecting the fuel injection time signal and the means for controlling the opening time of the fuel injector based on the selected signal after the start of the internal combustion engine. Fuel injection device.