JPS61106936A - Fuel supply control method during cranking of internal combustion engine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a fuel supply control method during cranking that improves the starting characteristics of an internal combustion engine.

(Technical background of the invention and its problems) When cranking an internal combustion engine, especially a gasoline engine, a predetermined procedure (cranking loop) that is prepared separately from a predetermined procedure (basic loop) that is applied after cranking is used. Based on this, the fuel injection valve opening time is set according to the engine temperature, and the standard valve opening time is set so that the amount of fuel supplied decreases as the engine temperature increases, and the standard valve opening time is set according to the engine speed during cranking. Accordingly, the present applicant has proposed a fuel supply control method that corrects the reference valve opening time so as to decrease the set standard valve opening time as the engine speed increases (Japanese Patent Laid-Open No. 57-2
No. 06736).

In this fuel supply control method, the reference valve opening time during cranking is set according to the engine temperature because a portion of the injected fuel adheres to the inner wall of the intake pipe or cylinder, and the amount of fuel evaporation increases. This is because the engine temperature changes depending on the engine temperature, and in particular when the engine temperature is low such as during a cold start, a large amount of fuel is supplied to the engine to obtain good starting characteristics. However, due to changes in the volatile content of the fuel due to engine neglect, the amount of fuel supplied to the engine during cranking may be reduced.
f b b@*It':! raft4gKft6f
t bz@@-1)<A16, due to changes in the properties of the fuel used, or due to changes in ignition performance due to a decrease in battery voltage of the ignition device, for example when it is cold,
The engine does not ignite after one or several spark discharges, and the cranking state continues for a long period of time without reaching state B (this is defined as a "complete explosion state") where the engine can operate independently due to complete ignition. As a result, the air-fuel ratio of the air-fuel mixture in the combustion chamber gradually becomes lynic, and as a result, a so-called smoldering or smoldering phenomenon occurs in the ignition plug, making ignition increasingly difficult.

(Summary of the Invention) The present invention has been made to solve the above problems, and provides a fuel supply control method that enables starting even when starting is difficult due to changes in fuel properties or low battery voltage. The purpose is to To achieve this objective, according to the invention, depending on a first predetermined parameter value when the internal combustion engine is in a cranking state,
In the fuel supply control method, the amount of fuel supplied to the engine is controlled according to a second predetermined parameter value when the engine leaves the cranking state, wherein when the engine is in the cranking state, the amount of fuel supplied to the engine is controlled according to a second predetermined parameter value. During cranking of an internal combustion engine, the fuel amount is controlled according to the second predetermined parameter value when the duration of the period of time is measured and the duration of the fuel amount is equal to or longer than a predetermined period of time. A fuel supply control method is provided.

(Example of the invention) Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 2 is an overall configuration diagram of an apparatus for carrying out the control method of the present invention. Reference numeral 1 indicates, for example, a four-cylinder internal combustion engine, and an intake pipe 2 is connected to the engine 1. A throttle body 3 is disposed in the middle of the intake pipe 2, and a throttle valve 31 (not shown) is provided inside. A throttle valve opening sensor 4 is connected to the throttle valve 31 to convert the opening of the throttle valve into an electrical signal and send it to an electronic control unit (hereinafter referred to as rEcUJ) 5.

A fuel injection valve 6 is provided in the intake pipe 2 between the engine 1 and the throttle body 3. The fuel injection valve 6 is connected to a fuel pump (not shown) and electrically connected to the ECU 3, and the opening time of the fuel injection valve 6 is controlled by a signal from the ECU 3.

On the other hand, an absolute pressure sensor 8 is provided immediately downstream of the throttle valve 3' of the throttle body 3 via a pipe 7, and the absolute pressure signal converted into an electrical signal by the absolute pressure sensor 8 is sent to the ECU 3. sent to. Further, an intake air temperature sensor 9 is installed downstream thereof, and this intake air temperature sensor 9 also converts the intake air temperature into an electrical signal and sends it to the ECU 3.

The main body of engine 1 is equipped with an engine water temperature sensor (hereinafter simply "
The water temperature sensor 10 consists of a thermistor, etc., and is inserted into the circumferential wall of the engine cylinder filled with cooling water, and the detected water temperature signal is sent to the EC.
Supply to U3.

Engine speed sensor (hereinafter referred to as rNe sensor) 1
1 and a cylinder discrimination sensor 12 are attached around the camshaft or crankshaft (not shown) of the engine, and the former Ne sensor 11 receives a TDC signal, that is, at a predetermined crank angle position every 180° rotation of the engine crankshaft, and the latter The cylinder discrimination sensor 12 outputs one pulse at each predetermined crank angle position of a specific cylinder, and these pulses are sent to E CtJ 5.

A three-way catalyst 14 is disposed in the exhaust pipe 13 of the engine 1 to purify HC, Co, and NOx components in the exhaust gas.

A 0□ sensor 15 is inserted into the exhaust pipe 13 on the upstream side of the three-way catalyst 14, and this sensor 15 detects the oxygen concentration in the exhaust gas and supplies the detected value signal to the ECU 3.

Furthermore, the ECU 3 includes a sensor 16 for detecting atmospheric pressure, an engine starter switch 17, and a battery electrode 1.
8 is connected, and a detected value signal from the sensor 16, a voltage signal from the battery electrode 18, and an on/off state signal of the starter switch 17 are supplied.

Next, details of the fuel control operation of the fuel supply control device configured as described above will be explained.

First, FIG. 3 shows the air-fuel ratio control of the present invention, that is, P, Cu2
A block diagram showing the overall program configuration of the control content of the valve opening time Toor of the fuel injection valve 6 in
It consists of a main program 1 and a subprogram 2, and the main program 1 is based on the engine rotation speed Ne<TDC
It performs control in synchronization with signals and consists of a cranking control subroutine 3 and a basic control program 4.
Subprogram 2 consists of an asynchronous control subroutine 5 when not synchronized with the TDC signal.

The basic calculation formula in cranking control subroutine 3 is Tout=T=c++ X KNa + Tv --
・"1ll. Here, TicR is the reference value for the opening time of the fuel injection valve 6 and is determined by the TIc,l table 6. KNll is the reference value for the opening time of the fuel injection valve 6. KNll is the cranking time value set according to the engine speed Ne. The correction coefficient is determined by the KN8 table 7. Tv is the valve opening time T in accordance with changes in battery voltage. It is a variable for increasing or decreasing LIT and is determined from the Tv child table.

Further, it is expressed as the basic calculation formula % formula % in the basic control program 4. Here, Ti is a reference value for the opening time of the fuel injection valve 6, and is calculated from the basic Ti map 9. TDEC and +'rAce are variables during deceleration and acceleration, respectively, and are determined by the acceleration and deceleration subroutine 10. Various coefficients such as K, A, ni, . . . are calculated by respective tables and subroutines 11. KTA is the intake air temperature correction coefficient calculated from the table based on the actual intake air temperature value, KTW is the fuel increase coefficient calculated from the table based on the actual engine water temperature value Tsi, and KA is the fuel increase after fuel cut calculated using the blue routine. The coefficient KPA is an atmospheric pressure correction coefficient determined from a table based on the actual atmospheric pressure value, KAST is the post-cranking fuel increase coefficient determined by a subroutine, and K and 1cT are constants that indicate the leanness of the mixture when the throttle valve is fully opened. KO2 is a 02 feedbank correction coefficient determined by a subroutine according to the actual oxygen concentration value in exhaust gas, and KLS is a constant that is a lean coefficient of the air-fuel mixture during lean/stoichiometric operation. Stoiki is 5toi-chiomet
The abbreviation ric indicates stoichiometric amount, that is, the stoichiometric air-fuel ratio.

In contrast, the formula for calculating the opening time TMA of the fuel injection valve 6, which is not synchronized with the TDC signal, in the asynchronous control subroutine 5 is TMA=TtAx KtGlt X KAST+
TV...Represented as (5). Here Ti
A is a fuel increase reference value during acceleration control that is asynchronous during acceleration, that is, not synchronized with the TDC signal, and is shown in TLA table 12.
Seek more.

K, , T are fuel increase coefficients during synchronous acceleration, after acceleration, and asynchronous acceleration calculated based on the water temperature increase coefficient KT- obtained from Table 13.

In addition, if the accelerator is repeatedly pressed before cranking or during cranking, if the asynchronous control subroutine executes the fuel increase during asynchronous acceleration, the fuel becomes rich and problems such as the ignition plug gets wet with fuel may occur. The asynchronous control subroutine is not executed when the cranking control subroutine is executed, since it will interfere with reliable starting.

FIG. 4 shows a flowchart of the main program 1 when controlling the valve opening time in synchronization with the TDC signal in the ECU 3, and the main program 1 consists of an input signal processing block (■), a basic control block (■), and a cranking control block (■). . First, in the input signal processing block I, when the engine ignition switch is turned on, the CPU in the ECUS is initialized (Step 1), and the TD is started by starting the engine.
A C signal is input (step 2). Then the atmospheric pressure value T from each sensor, which is all the basic analog values,
P,, absolute pressure value PIA, engine water temperature value TW, intake air temperature value TA, battery voltage value ■, throttle valve opening value θ
th, the output voltage value ■ of the o□ sensor, the on/off state signal of the starter switch 17, etc. are read into the IC1ls and the necessary values are stored (step 3). Next, the elapsed time from the first TDC signal to the next TDC signal is counted, and the engine speed Ne is determined based on that value.
Calculate and store in the same <ECUS (Step 4)
. Next, in the basic control block (2), as will be described in detail later, it is determined whether the engine is in a cranking state (step 5). If the answer is affirmative (Yes), the process is sent to the cranking control subroutine of the cranking control block ■, in which Tic* is determined based on the engine water temperature value TW using the Tic* table (step 6), and the engine speed value Ne is The correction coefficient is determined to be 0 using the K) Ill table (step 7).

Then, from the Tv child table, the battery voltage correction variable T
Determine v, step 8), insert each value into the previous generation (1), and enter T. Calculate LIT (step 9).

Further, if the answer is negative (NO) in step 5, it is determined whether the engine is in a state where the fuel should be cut (step 10), and the answer is affirmative (step 10).
If yes), then T. The uTO value is set to zero and a fuel cut is performed (step 11).

On the other hand, if the answer is determined to be negative (No) in step IO, each correction coefficient K? A+ K TW, K
AFC+KPAI Kasd+K, 1ot, KO
z, Kts, Kywt etc. and correction variable T DE
Calculate C+T ACc+Tv (Step 12
). These correction coefficients and variables are determined by subroutines, tables, and the like.

Next, Ti stored in the map is selected according to each data of the engine rotation value Ne and the absolute pressure value pra (step 13). Then, based on the correction coefficient value, correction variable value, and reference value obtained in step 12.13 above, T is determined by cutting allowance (2). Calculate ut (step 14)
. And thus obtained T. The fuel injection valve 6 is operated based on the value of UT (step 15).

As mentioned above, in addition to controlling the opening time of the fuel injection valve 6 in synchronization with the TI)C signal mentioned above, it also controls the opening time of the fuel injection valve 6, not in synchronization with the TDC signal, but in synchronization with a pulse train with a constant time interval. Although asynchronous control is performed to control the fuel injection valve 6, detailed explanation thereof will be omitted.

Next, the specific contents of the cranking determination subroutine according to the present invention will be explained in detail below.

FIG. 1 shows a flowchart of a subroutine for determining whether or not the engine is in a cranking state in step 5 of FIG. 4. In this cranking determination subroutine, first, it is determined whether the starter switch 17 is on or not (step 1), and if it is not on, it is assumed that cranking is not in progress, and the process moves to the basic control loop (step 2). If the engine rotation speed Ne is a predetermined cranking rotation speed Ncm (for example, 400 rpm)
If the former is greater than the latter, it is determined that cranking is not in progress and the process proceeds to the basic control loop; if the former is less than the latter, the process proceeds to step 4).

In step 4, it is determined whether or not the water temperature sensor 10 is normal by a method that will be described in detail later. If normal, the process proceeds to step 5; if abnormal, the process proceeds to a cranking control loop (step 6). ).

In step 5, the cranking state is maintained for a predetermined period of time, e.g.
It is determined whether or not -E has continued for more than 2 seconds, and the answer is affirmative (Y
es), move to the basic control loop (step 2)
, if negative (No), the process moves to a cranking control loop (step 6).

FIG. 5 shows a flowchart of a subroutine for determining whether or not the water temperature sensor 10 is normal. First, data v1 corresponding to the engine water temperature value T,1 output from the water temperature sensor 10 is read and stored (step 1).
, then the data V714 is the specified value (upper limit value) Vt
Determine whether it is greater than or equal to wo (step 2), and if the answer is negative (No), continue with the specified value (lower limit value)
Determine whether it is below VT%IL (Step 3)
. If the answer to step 3 is negative (No), the data vT, 1 is Vyw+, <Vtw<Vtwu It is determined that the water temperature sensor 10 is normal, and the process proceeds to step 5 in FIG.

The result of the determination in step 2 or 3 in Figure 5 is affirmative (
Yes), vyw>vyo8 or Vyiv<V
It is determined whether the state of twt has been maintained for a predetermined period of time, for example, 2 seconds or more (step 4), and the answer is affirmative (Yes).
If so, it is determined that the water temperature sensor 10 is abnormal and the process proceeds to step 6 in FIG. 1. If the answer is negative (No), that is, the predetermined time has not elapsed, the process proceeds to step 5 in FIG. The reason why it is not immediately declared abnormal when the engine water temperature value T,1 exceeds a predetermined value range is to absorb temporary output fluctuations of the water temperature sensor 10 due to noise or the like. - Incidentally, a fuel supply control method in the cranking mode and basic mode when the water temperature sensor 10 is abnormal has been proposed by Junto Motode (Japanese Patent Application Laid-Open No. 58-202336), and the outline thereof is as follows: In a fuel supply control method in which a fuel metering device that controls the amount of fuel to be controlled is electrically controlled by a signal representing the operating state of the engine such as an engine water temperature signal, the output temperature signal of a water temperature sensor that detects the engine water temperature is used to control the water temperature sensor. detects an abnormality in the engine, and in the event of an abnormality, pseudo temperature data is sequentially output in place of the temperature signal from the time the starter switch is turned on, and the amount of fuel supplied during cranking mode is gradually increased based on the pseudo temperature data to start the engine. The phantom temperature is maintained at a predetermined value in the basic mode. Therefore, when the water temperature sensor 10 is abnormal, the compensation operation for the water temperature sensor abnormality is executed, so that the engine can be brought to a complete explosion state more reliably by continuing the cranking mode. For this reason, if the determination result in step 4 in FIG. 1 is negative (No), the cranking loop in step 6 is executed.

FIG. 6 is a block diagram of a control device that determines the cranking state based on the flowcharts shown in FIGS. 1 and 5, and is built in the ECU 3 shown in FIG. 2.

In the figure, the engine water temperature T, and the value register 60 contains the engine cooling water temperature value T output from the water temperature sensor 10. The data vT11 of the temperature differential 6 corresponding to 6 is input to one input terminal A of the comparator 65, 66. A". Meanwhile, each of these comparators 65, 6
The other input terminals B and B' of 6 have an engine water temperature upper limit value V TWH memory 61 and an engine water temperature lower limit value V 71, respectively.
Upper limit value data V from B memory 62 □.

Lower limit value data VTWL is input. The engine rotation speed Me value register 63 is set with data Me corresponding to the reciprocal 1/Ne of the engine rotation value Ne output from the engine rotation speed sensor 11 shown in FIG. input terminal A”.

The other input terminal B'' of this comparator 67 receives data M @ cll corresponding to the cranking rotational value N.CI+.
M. was memorized. Cllll child memory 64 is input with data M and C@ of the cranking rotation values.

When the ignition switch 71 is on, the constant voltage circuit 69 converts the voltage of the battery 72 into a predetermined constant voltage +VCC, outputs it, and applies it to the control device. Further, the initial set pulse generation circuit 73 outputs a single pulse Pi only when a voltage is applied from the constant voltage circuit 7o directly connected to the battery 72, that is, only when the battery 72 is connected, and the subsequent flip-flop circuit Set 78. The level correction circuit 68 corrects the voltage signal input when the starter switch 17 is on to a signal of a predetermined level and outputs the signal, and outputs the signal to the AND circuit 86 and the capacitor c3. It is added to the input side of a differentiating circuit 81 composed of a resistor R3 and a diode D.

The comparator 67 determines that the engine revolution value Ne is a predetermined cranking revolution value N. It determines whether or not it is smaller than C11, and corresponds to data Me and M corresponding to the current engine rotation value Ne input from the Me value register 63, and cranking rotation values N and CR input to the Cllll child memory 64. Data M. Compare Me > MeeR
In the case of (A ''> B ''), that is, when the engine speed value Ne is lower than the cranking speed values N, c, and l, the output becomes a high level (hereinafter referred to as "1"), and output 1 is added to the AND circuit 86kl. . This AND circuit 86 includes a comparator 67 and a level correction circuit 68.
When each signal 1 is inputted from the engine is in the cranking state, the AND circuit 86 inputs the output 1 to one input terminal of the AND circuit 88 and the inverter 8.
Add to 7. On the other hand, when the cranking state is not present, the output of the AND circuit 86 is at a low level (hereinafter referred to as "0").
becomes. This output 0 is inverted by an inverter 87 and sent as a signal 1 to the basic loop control circuit 89 via an OR circuit 80.
added to.

Comparator 65 receives temperature data vT1. This is to determine whether or not l is larger than the upper limit value VTH□.The input data Vll and ■T□ are compared, and when Vt+m>Vtw,l, that is, the temperature data V7H exceeds the upper limit value V TWO. Sometimes the output is 1. Comparator 66 receives temperature data VTII
This is to determine the lower limit of input data VT, 1 and VT
IIIL, the output becomes 1 when VTl,l<■T11L, that is, when the temperature data v7□ is lower than the lower limit value VTIIL. Therefore, these comparators 6
When signal 1 is output from 5 or 66, that is, when temperature data VT, 1 is outside the predetermined range.
1 water temperature sensor 10 is determined to be abnormal. When the outputs of these comparators 65 and 66 are 0, the output of the monostable multi-bi break 76 is 0.

On the other hand, the output 1 of the output terminal Q of the flip-flop circuit 78, which has been set to the set state by the initial cent pulse Pi, is applied to one input terminal of the AND circuits 79 and 84.
These AND circuits 79.degree. 84 are in a state where they can be opened.

An abnormality has occurred in the water temperature sensor 10, and the output data V7H of the register 60 is equal to or higher than the upper limit value V71111 or lower limit value V T
When it becomes less than wL, the output of comparator 65 or 66 becomes 1, and this output 1 is connected to capacitor CI via OR circuit 74.
, resistor RI + diode D, a differentiating circuit 75. It is applied to one input terminal of the suppression circuit 77 and the reset input terminal of the monostable multivibrator 76 . Differentiating circuit 75 outputs a trigger pulse signal at the rising edge of the input signal and applies it to monostable multivibrator 76 . When a trigger pulse is applied to the monostable multivibrator 76, the monostable multivibrator 76 is activated and its output becomes 1 for a predetermined period of time, that is, 2 seconds as shown in step 4 of FIG. Furthermore, the output side of the monostable multipipe rake 76 is connected to the other input terminal of the suppression circuit 77 through a capacitor C2, and this input terminal is further connected to the power supply +VCC through a parallel circuit of a resistor R2 and a diode D2. ing. This diode D2
is for regulating the input voltage level of the suppression circuit 77 to a predetermined value below the power supply voltage +Vcc.

When the output of the monostable multivibrator 76 becomes O after 2 seconds, that is, when the output falls from 1 to 0, the capacitor Ct is discharged. The input to the suppression circuit becomes 0 from when the capacitor C2 is discharged until it is charged again. At this time, the signal l from the OR circuit 74 is transmitted to this suppression circuit 77.
is applied to one input of the OR circuit 74, that is, if the output l of the OR circuit 74 is sustained for 2 seconds or more, the suppression circuit 7
7 becomes 1 and resets the flip-flop circuit 78. At this time, it is determined that the water temperature sensor 10 is abnormal.

The monostable multivibrator 76 is reset when the output of the OR circuit 74 changes from 1 to O.

Therefore, if the output 1 of the OR circuit 74 is generated once and becomes 0 before 2 seconds elapse, the output of the OR circuit 74 becomes 0, and at the same time, the output of the monostable multi-by-break 76 also becomes 0, so the flip-flop circuit It will not be reset on the 7th,
Therefore, at this time, it is not determined that the water temperature sensor 10 is abnormal.

When the output of the water temperature sensor 10 is determined to be abnormal and the flip-flop circuit 78 is reset, the output Q becomes 0 and the output Q becomes 1.
This output 1 is applied to the other input terminal of the AND circuit 88 via the OR circuit 85. At this time, if the signal l is also applied to one input terminal of this AND circuit 88,
That is, when the engine 1 is in a cranking state and the water temperature sensor 10 is abnormal, the AND circuit 88 applies an output l to the cranking loop control circuit 90.

On the other hand, when the starter switch 17 is turned on, the differentiating circuit 81 to which the signal 1 output from the level correction circuit 68 is applied outputs a trigger pulse signal at the rising edge of the input signal and applies it to the monostable multivibrator 82 . The monostable multi-bi break 82 is activated when a trigger pulse is applied, and its output becomes 1 for a predetermined period of time, that is, 5 seconds as shown in step 5 of FIG. 1 above. This output 1 is the inverter 83
After being inverted by , the signal is applied to the other input terminal of the AND circuit 79 to close the AND circuit 79 and is applied to the other input terminal of the AND circuit 84 . At this time, if signal 1 is also applied to one input terminal of this AND circuit 84, that is, if the water temperature sensor is normal, the AND circuit 84 is connected to the other input terminal of the AND circuit 88 via the OR circuit 85. Add output l. At this time, if the signal 1 is applied to one input terminal of the AND circuit 88, that is, if the engine is in a cranking state, the AND circuit 88 applies an output 1 to the cranking loop control circuit 90. That is, even when the water temperature sensor is normal and the duration of the cranking state is less than 5 seconds, the AND circuit 88 applies an output of 1 to the cranking loop control circuit 90.

Output 1 of monostable multivibrator 82 becomes 0 after 5 seconds.
When this happens, the AND circuit 84 becomes a closed state and at the same time the AND circuit 79 becomes an open state.

At this time, if signal 1 is applied to one input terminal of this AND circuit 79, that is, if the water temperature sensor 10 is normal and the cranking state continues for 5 seconds or more, the AND circuit 79
9 applies the output 1 to the basic loop control circuit 89 via the OR circuit 80.

When the basic loop control circuit 89 and the cranking loop control circuit 90 receive the signal 1 from the OR circuit 80 and the AND circuit 8B, respectively, the valve opening time T is determined according to a predetermined program. U? is calculated, and a control signal corresponding to the calculated T out value is outputted, which is applied to the fuel injection valve 6 in FIG. 2 to control the amount of fuel supplied to the engine.

In the above embodiment, the duration of the cranking state is measured by the monostable multivibrator 82 as a timer, but the duration can be measured by a TDC counter that counts the number of pulses of the TDC signal. It's okay.

(Effects of the Invention) As detailed above, according to the present invention, the duration of the cranking state of the internal combustion engine is measured, and if this duration is longer than a predetermined period, the engine is in the cranking state. In the basic mode after cranking, the amount of fuel supplied to the engine is controlled, and the air-fuel mixture in the combustion chamber, which is in an over-rich air-fuel ratio state, is made lean, thereby creating conditions that allow ignition. Even in a starting situation, there is a higher possibility of achieving a complete explosion, and the engine starting characteristics are improved.

[Brief explanation of the drawing]

FIG. 1 is a flowchart of a cranking determination subroutine according to the present invention, FIG. 2 is an overall block diagram of a fuel supply control device for an internal combustion engine to which the method of the present invention is applied, and FIG. 3 is an electronic control diagram of FIG. A block diagram showing the overall program configuration of the control contents of the fuel injection valve opening time T Ot+T in the unit (ECU > 5), Figure 4 is a flowchart of the main program, and Figure 5 shows the water temperature sensor in step 4 of Figure 1. The flowchart of the subroutine for determining whether it is normal or not, FIG.
FIG. 6 is a block diagram showing an embodiment of a control device for carrying out the flowchart of FIG. 5 and FIG. 1... Internal combustion engine, 5... ECU. 6...Fuel injection valve, 10...Water temperature sensor, 11
...Ne sensor, 17...Starter switch, 63...Me value register, 64...M sc m
Value memory, 65.66.67... Comparator, 76.82... Monostable multivibrator, 78...
-Flip-flop circuit, 89...Basic loop control circuit, 90...Cranking loop control circuit.

Claims (4)

[Claims] 1. Fuel supply controlling the amount of fuel supplied to the internal combustion engine in response to a first predetermined parameter value when the internal combustion engine is in a cranking condition and in response to a second predetermined parameter value when the engine leaves the cranking condition, respectively. In the control method, when the engine is in a cranking state, a duration of the cranking state is measured, and when the duration is equal to or longer than a predetermined period, the amount of fuel is increased according to the second predetermined parameter value. A fuel supply control method during cranking of an internal combustion engine, characterized in that the control is executed. 2. 2. The method of controlling fuel supply during cranking of an internal combustion engine according to claim 1, wherein the first predetermined parameter includes at least engine temperature. 3. The fuel amount is controlled in accordance with the second predetermined parameter value when the detected value of the engine temperature is within a predetermined normal value range and the duration period is equal to or longer than a predetermined period. A fuel supply control method during cranking of an internal combustion engine according to claim 2. 4. When cranking an internal combustion engine according to claim 1, the cranking state is a state in which the rotational speed of the engine is below a predetermined cranking rotational speed and the starter of the engine is in an operating state. Fuel supply control method.