JPS61210251A - Idle running time controller for internal-combustion engine - Google Patents

Abstract

PURPOSE:To make a yet wider idling speed controllable, by regulating ignition timing and injection timing either to an optimum value conformable to an air-fuel ratio simultaneously with regulating the air-fuel ratio. CONSTITUTION:A controller bearing the above caption feedback-controls a fuel feeding device M4 through a feedback controlling device M7 according to the detecting value of an air-fuel ratio detecting device M3 at a time when that an engine M1 is in an idle state is judged by an idle state judging device M6 on the basis of the detected result of a running state detecting device M2. In this case, there is provided with an air-fuel ratio altering device M8 which alters the desired air-fuel ratio used by the said controlling device M7 according to an engine speed. In addition, there are provided with a feed timing controlling device M9, controlling the fuel feed timing of the fuel feeding device M4 according to the engine speed and the detected value of a suction air quantity and an ignition timing controlling device M10 indicating the ignition timing commensurate to the engine speed to an ignition device M5.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an idle control device for an internal combustion engine, and particularly to an internal combustion engine in which the air-fuel ratio is controlled to be leaner than the stoichiometric air-fuel ratio during idle. The present invention relates to a control device.

[Conventional technology] In recent years, with the deterioration of the energy situation and the tightening of exhaust gas regulations to prevent air pollution, research has been conducted into methods and devices to further improve the thermal efficiency of internal combustion engines and make exhaust gas cleaner.
developed and offered to the market.

One of these is the air-fuel ratio (A/F), a method that controls the weight ratio of air and fuel in the mixture sent to the engine to lower harmful components in exhaust gas and improve thermal efficiency. It is being

Among these methods of controlling the air-fuel ratio, the air-fuel ratio is not only controlled based on the theoretically determined stoichiometric air-fuel ratio, but also when the engine load and rotation speed are within a predetermined range. to a high state, a so-called lean state,
A method has been proposed that has good thermal efficiency and controls harmful components in exhaust gas to a small extent.

The system for controlling the air-fuel ratio to a lean state as described above (hereinafter referred to as a lean burn system) is also applied during idling. In this case, it is possible to control the output by adjusting the air-fuel ratio, which can contribute to stabilizing the rotation speed, so a system that attempts to assist the adjustment of the idle rotation speed from the point of view of the air-fuel ratio may be considered. It will be done. That is, when the rotational speed decreases, the air-fuel ratio is lowered and the output is increased, and when the rotational speed increases, the air-fuel ratio is increased and the output is decreased, thereby making it possible to adjust the idle rotational speed.

[Problems to be Solved by the Invention] The idle speed control by adjusting the air-fuel ratio achieves stabilization of the feedback control in a normal idle state, and can smoothly control the speed to a target speed.

However, when trying to control the output by adjusting only the air-fuel ratio, the range of possible changes in the air-fuel ratio in response to rotational fluctuations is narrow (for example, 14.7 to 15.5), and there are limits to this control. That is, the air-fuel ratio at which misfires begin is relatively close to the stoichiometric air-fuel ratio, and if the air-fuel ratio becomes leaner than that, misfires occur, and if the air-fuel ratio is too rich than the stoichiometric air-fuel ratio, problems arise with emissions.

Another system used to stabilize idle rotation is one that advances the ignition timing when the rotation speed decreases and retards it when the rotation speed increases, thereby adjusting the output and controlling the rotation speed. However, in the lean burn system, there are limits to independently changing the ignition timing, and this could not be an effective means.

An object of the present invention is to control the idle speed over a wider range by adjusting the air-fuel ratio and simultaneously adjusting the ignition timing and injection timing to optimum values according to the air-fuel ratio.

[Means for Solving the Problems] As a means for solving the above problems, the present invention employs the following configuration.

That is, as shown in FIG. 1, the present invention includes an operating state detecting means M2 that detects the operating state of the internal combustion engine M1 including the engine speed and intake air amount, and a means for detecting the operating state of the internal combustion engine M1 from the exhaust gas of the internal combustion engine M1. an air-fuel ratio detection means M3 for detecting an air-fuel ratio of a mixture of supplied air and fuel;
an ignition means M5 for igniting the internal combustion engine M1 at a timing according to an instruction; and determining whether or not the internal combustion engine M1 is in an idle state based on the detection result of the operating state detection means M2. an idle state determining means M6 for determining the idle state; and when the idle state detecting means M6 determines that the idle state is present, the detected value of the air-fuel ratio detecting means M3 is fed back to supply the fuel amount to the fuel supply means M4. Feedback control means M7 for instructing and controlling the actual air-fuel ratio to a target air-fuel ratio exceeding the stoichiometric air-fuel ratio; air-fuel ratio changing means M8 for changing the target air-fuel ratio used by the feedback control means M7 according to the rotational speed detected by the operating state detection means M2; supply timing control means M9 for controlling the supply timing of the fuel supplied from the fuel supply means M4; and instructing the ignition means M5 to set the ignition timing according to the rotational speed detected by the operating state detection means M2. The gist of the present invention is an idling control device for an internal combustion engine, comprising: an ignition timing control means MIO;

Refers to a group of detection means such as sensors that detect intake air temperature, engine speed, exhaust temperature, load on the internal combustion engine such as throttle valve opening, and running speed in the case of a vehicle.

The air-fuel ratio detection means M3 detects the air-fuel ratio of the air-fuel mixture before combustion using a sensor such as a so-called lean mixture sensor that measures the oxygen concentration in the exhaust gas when a lean air-fuel mixture is combusted. It is something.

The fuel supply means M4 refers to, for example, a fuel injection valve and its drive circuit that adjusts and supplies the amount of fuel injected to intake air. The ignition means M5 is an igniter,
A device that ignites an air-fuel mixture, such as a spark plug.

The idle state determining means M6 is the driving state detecting means M2.
Detection results, for example, the closed state of the throttle valve opening,
This is to determine whether or not the vehicle is in an idle state, such as when the vehicle is stopped.

The feedback control means M7 is composed of an electronic circuit, a computer, etc., and controls the air-fuel ratio detection means M3 and the fuel supply means M4 so that the air-fuel mixture supplied to the internal combustion engine M1 reaches a set target air-fuel ratio in a lean state. This is used to perform feedback control.

The air-fuel ratio changing means M8 is similarly composed of an electronic circuit or a computer, and changes the target air-fuel ratio used by the feedback control means M7 according to the rotational speed in a direction that reduces the difference from the set value of the rotational speed. This changes the target air-fuel ratio.

The supply timing control means M9 is similarly composed of an electronic circuit or a computer, etc., and adjusts the supply timing of the fuel supplied into the intake air by the fuel supply means M4 according to the rotation speed and the amount of intake air. It is something. This is to change the fuel supply timing to the optimum value for output and emissions in response to the air-fuel ratio changed by the air-fuel ratio changing means M8 in response to changes in the rotational speed.

The ignition timing control means M10 is similarly composed of an electronic circuit, a computer, etc., and adjusts the ignition timing ignited by the ignition means M5 in accordance with the rotation speed. This is to change the ignition timing in response to the air-fuel ratio changed by the air-fuel ratio changing means M8 in response to changes in the rotational speed, and is to select the optimum ignition timing for combustion. The supply timing control means M9 and the ignition timing control means M1
0 means that the timing is controlled according to the number of rotations,
Since the air-fuel ratio is set corresponding to the rotational speed, even if the timing of both means M9 and Mlo is controlled according to the value of the air-fuel ratio, it is the same as the control performed according to the rotational speed.

[Function] If the number of revolutions at idle increases or decreases due to some reason such as an electrical load, the air-fuel ratio changing means M8 changes the internal combustion engine M.
Air-fuel ratio (A/F) of the lean mixture supplied to 1
changes in a direction that suppresses fluctuations in rotational speed. In other words, if the number of revolutions falls below the set number of revolutions, the A/F will be lowered to increase the number of revolutions by enriching the fuel, and conversely, if the number of revolutions rises above the set number of revolutions, the A/F will be reduced. Try to raise the engine to thin the fuel and lower the rpm.

At this time, the supply timing control means M9 and the ignition timing control means M10 also work to adapt to the change in A/F. That is, since the fuel supply time becomes shorter or longer as the rotational speed increases or decreases and the A/F increases or decreases, the supply timing control means M9 adjusts the supply end timing in order to accurately reflect the supply base in the air-fuel mixture. In order to match the injection timing, the injection timing is delayed or advanced. In addition, the ignition timing control means MIO similarly changes the output because the combustion pattern changes depending on the up and down of the A/F.

Select the optimal ignition timing considering emissions, etc.

Both control means M9. By cooperating with M10 and the air-fuel ratio changing means M8, the range of A/F changes by the air-fuel ratio changing means M8 is expanded, and a larger capacity is exhibited for stabilizing the rotational speed during idling.

[Example] Embodiments of the present invention will be described in detail below based on the drawings.

FIG. 2 is a schematic configuration diagram of an embodiment of a control device including an internal combustion engine and its peripheral devices, in which 1 is the internal combustion engine, 2 is an electromagnetic fuel injection valve as part of the fuel supply means M4, and 4 6 is a well-known lean sensor serving as air-fuel ratio detection means M3 for detecting the oxygen concentration in the exhaust gas from the internal combustion engine 1 from the limit current;
serves also as a part of the fuel supply means M4, and also serves as an idle state determination means M6. Feedback control means M7. Air-fuel ratio changing means M8. Electronic control circuits are shown as supply timing control means M9 and ignition timing control means M10, respectively.

Further, as the operating state detection means M2 of the internal combustion engine 1, as shown in the figure, an intake air temperature sensor 8 degrees, a throttle sensor +112. Internal combustion engine body 1
A semiconductor-type intake pressure sensor 18, which is installed in a surge tank 16 provided in the intake pipe 14 of the engine, detects the intake pipe pressure. A water temperature sensor 20 that detects the temperature of the cooling water of the internal combustion engine 1. A rotation speed sensor 24 is installed facing the rotor 22a inside the distributor 22 and detects the rotation speed of the internal combustion engine 1 by generating 24 pulses every two revolutions of a crankshaft (not shown). Similarly, a group of sensors such as a cylinder discrimination sensor 25 which generates one pulse per revolution of the crank are provided.

A high voltage pulse generated in an igniter 26 as part of the ignition means M5 is supplied to the distributor 22, and the distributor 22 is screwed into the upper part of the cylinder 28 of the internal combustion engine 1 in synchronization with the combustion cycle of each cylinder. This high voltage is applied to the ignition plug 30 of the ignition means M5, which is closed, to ignite the air-fuel mixture. or,
32 is a catalytic converter provided in the exhaust pipe 34 of the internal combustion engine 1.

Next, the internal configuration of the electronic control circuit 6 and the electrical signal system will be explained. The electronic control circuit 6 includes a central processing unit (CPtJ) 60 that inputs data, performs calculations, and controls according to a predetermined program, and a read-only memory (ROM>62) that stores control programs and the like in advance.
, a temporary storage memory (RAM) 64 in which data etc. can be freely written and read, an input port 5 for inputting signals from various sensor groups for detecting the operating state of the internal combustion engine 1;
Output port lower that outputs control signals to the igniter 26, fuel injection valve 2, etc., CPtJ60. A data bus 68 and a key switch 71 that interconnect the above-mentioned elements such as the ROM 62
The power supply circuit 75 is connected to a battery 73 via a power supply circuit 75 and supplies a stabilized voltage to the entire electronic control circuit 6. The input port 5 includes a pulse input section 65a that inputs pulse signals from the rotation speed sensor 24 and the cylinder discrimination sensor 25, and an intake air temperature sensor 8. Throttle sensor 12, intake pressure sensor 1B, lean sensor 4. It has an analog input section 65b into which an analog signal corresponding to each detection value from the water temperature sensor 20 is input.

On the other hand, a crank angle (not shown) of the internal combustion engine 1 is detected by a signal from the rotation speed sensor 24, and in synchronization with this, a signal is generated to drive the igniter 26 at a time determined according to the air-fuel ratio, and a signal determined according to the fuel injection amount. A control signal that opens the fuel injection valve 2 for the fuel injection time at a time determined according to the air-fuel ratio, and a constant voltage signal that is applied to the lean sensor 4 to detect the oxygen concentration from the limit current in the lean sensor 4. is output via the output port lower. The fuel injection valve 2 is controlled and opened by the control signal, and fuel is injected into the intake pipe 14 by receiving fuel from a fuel pump (not shown).

Next, FIG. 3 (a) shows the processing performed by the electronic control circuit 6.
, (b) and Figure 4 (a), (b).

The control performed by the internal combustion engine control device of this embodiment will be explained with reference to the flowchart (c). Figure 3 (
A) represents the actual fuel injection amount TAtJ and injection timing calculation routine, FIG. 3(B) represents the injection timing setting routine for the 30' CA interrupt, FIG. FIG. 4(b) shows an ignition timing setting routine, and FIG. 4(c) shows a time coincidence interrupt routine for ignition execution. The key switch 71 is closed and turned on. First, in step 100, the intake pipe pressure P detected by the intake pressure sensor 18 via the input port 5 is
m, engine rotation speed N detected by rotation speed sensor 24
E, cooling water temperature TW detected by the water temperature sensor 20;
A process is performed to read the operating state of the internal combustion engine, such as the opening degree Op of the throttle valve 10 detected by the throttle sensor 12, and the output signal VQ of the lean sensor 4. In the subsequent step 102, the basic amount determined according to the intake pipe pressure Pm, which is approximately proportional to the load of the internal combustion engine, that is, the intake air amount per cylinder to the internal combustion engine 1, is corrected according to NE, and the stoichiometric air-fuel ratio is determined. Based on the control, a process for determining the basic fuel injection amount (basic fuel injection time) To is performed. That is, the basic fuel injection time Tp is calculated from Tp=krxPmxK (NE), where kr is a constant and K(NE) is a correction coefficient according to NE. In step 104 following step 102, a correction coefficient K including various factors for correcting the basic fuel injection amount Tp is calculated from each signal value indicating the operating state read in step 100. This correction coefficient includes, for example, a transient correction coefficient FTC determined from the rate of change in the signal OP from the throttle sensor 12, a warm-up increase coefficient FWL determined according to the value of the water temperature Tw read from the water temperature sensor 20, etc. This includes:

After the process in step 104, it is determined in step 106 whether or not it is in an idle state. If it is in an idle state, the process proceeds to step 108; if not, it is in step 11
Proceed to step 2. Both step 108 and step 110 are for determining whether the lean control condition is satisfied, for example, it is determined whether TW≧predetermined value or whether the warm-up increase has been completed. If the lean condition is not satisfied in either step 108 or 110, the process proceeds to step 114, and the lean correction coefficient FLEAN is set to 1.0.
It is said that If the lean condition is satisfied in step 110, the FL when not in the idle state is determined in step 116.
Calculate EAN. Similarly, if the lean control condition is satisfied in step 108, the lean correction coefficient FLEAN is determined in step 112 from map 1 expressed in the graph shown in FIG. 5 based on NE. Next step 11
8, the above lean correction coefficient FLEAN and correction coefficient K
Correct the basic fuel injection amount TP according to the following formula using
A process is performed to calculate the actual fuel injection gFIITAU.

TAtJ=TPXFLEANXK Therefore, in the steady state after complete warm-up, the controlled air-fuel ratio is FL
When EAN=1, the air-fuel ratio becomes the stoichiometric air-fuel ratio, and as FLEAN is smaller than 1, the air-fuel ratio becomes thinner than the stoichiometric air-fuel ratio.

In this way, the processing of this routine is temporarily completed. After this TAU
Using the value of TAU, the amount of fuel corresponding to the value of TAU is injected from the fuel injection valve 2 in accordance with the injection timing, for example, in a fuel injection timing setting routine as shown in FIG. In map 1 of step 112 above, when the rotation speed increases, FLEAN decreases, and when the rotation speed decreases, FLEAN decreases.
Since TAU is set to increase, TAU also changes in the opposite direction to the rotational speed, and as a result, the air-fuel ratio increases as the rotational speed increases and decreases as the rotational speed decreases.

Next, the injection timing calculation process that will be executed subsequently will be explained. Using NE and Pm already detected in step 120, a fuel injection timing basic correction value INJBSE is determined according to map 4 expressed in the graph shown in FIG. What is shown in Fig. 8 is a curved surface that is convex in the increasing direction of INJBSE, and as NE and Pm increase, I
NJBSE is decreasing, and when both NE and pm increase, the degree of decrease is the most significant.

Subsequently, in step 122, it is determined whether the engine is in an idle state, and if it is in an idle state, the process proceeds to step 124. In step 124, the fuel injection timing sub-correction value IN is calculated according to map 5 expressed in the graph shown in FIG.
Find JSUB. Map 5 is set so that as FLEAN rises, INJSUB falls.

When FLEAN performs lean control in idle state,
Since it is uniquely determined based on NE, the side correction value INJSUB is ultimately set according to NE. If the idle state is not determined in step 122, INJSUB for the case in which the vehicle is not in the idle state is calculated in step 126, and the process proceeds to step 128. Next, in step 128, all correction values INJ are set to INJB.
It is determined by the sum of SE and INJSUB.

Fuel in an amount of TAU determined by the calculation process is injected into the intake air at that time. Since INJ is added to the injection reference angle of the crankshaft, the injection timing is retarded as INJ increases.

Next, the injection timing setting routine shown in FIG. 3(b), which is interrupted every 30'CA, will be explained. First step 130
BTDC of the cylinder to be injected at (>60' before top dead center)
If it is BTDC60' CA, then in step 132, the time required for the engine to rotate 30° OA is determined based on the latest signal from the rotation speed sensor 24. Next, in step 134, the injection timing INJ ('CA) obtained in step 128 of the TAU and injection timing calculation routine is converted into time TINJ based on the above-mentioned required time. Next, in step 136, the injection start time TS is calculated from the current time TN and TINJ (TS=TN+TINJ). Next, in step 138, TS and T obtained in the routine are
From AU (time unit), the end time TE of ejection 9A is determined by calculation (TE=TS+TAU>.Next, step 1
At step 40, the values of TS and TE are set in a timer for injection execution, and the processing of this routine is temporarily terminated.

Thereafter, in the timer interrupt processing, fuel is injected from the fuel injection valve 2 at time TS, and the injection is stopped at time TE.

Next, the ignition timing calculation routine shown in FIG. 4(a) will be explained. This routine may be executed every 60 degrees of crank angle, or may be executed even faster during the main routine. First, using the NE already detected in step 150, the ignition timing basic correction value TI-ITBs is calculated according to map 2 expressed in the graph shown in FIG.
Find E.

Map 2 is set so that as the rotational speed increases, THTBSE also increases. Next, in step 152, it is determined whether or not the engine is currently in an idle state. If the engine is in an idle state, the FL determined in step 15 is determined.
Using EAN, the ignition timing side correction value THTSUB is determined according to Map 3 expressed in the graph shown in FIG. Map 3 is set so that THTSUB falls as FLEAN rises. Since FLEAN is uniquely determined based on NE when lean control is executed in an idle state, the above-mentioned side correction value THTS is ultimately obtained.
UB is set according to NE. When the process advances from step 152 to step 156, THTStJB in a non-idle state is determined. Next, in step 158, the total correction value THT is changed to THTBSE and T.
It is determined by the sum with HTSLIB. Finally, in step 160, THT is converted into time, and the crank angle interrupt position for ignition control and the time from that position to the final ignition timing are calculated.

In this way, the processing of this routine is once completed, and after this, THT
The ignition timing is set using the value of, for example, in the ignition control routine shown in FIGS. Since T HT is subtracted from the ignition reference angle of the crankshaft, the ignition timing is advanced as T HT increases.

Next, the ignition timing set routine shown in FIG. 4(b) and the time coincidence interrupt routine shown in FIG. 4(c) which are printed every 30'G:A will be explained.

First, in step 170 of the ignition timing setting routine, it is determined whether the timing of the pulse output from the rotation speed sensor 24 is at the crank angle interrupt position determined in step 160 of the ignition timing calculation routine, that is, whether it is the ignition timing interrupt timing. It is determined whether or not. If it is not the interrupt timing, the process is temporarily terminated. If it is interrupt timing, then in step 172, the final ignition timing obtained in step 160 of the routine is used to find the time from the current time to the final ignition timing, and the time is calculated in the time matching interrupt routine described later. Set the timer to start an interrupt.

In the time coincidence interrupt routine of FIG. 4(c), when the timer reaches the final ignition timing, the power to the igniter 26 is turned off in step 180, and at this point the spark plug 30 is discharged and the air-fuel mixture is is ignited.

As mentioned above, the fuel injection timing and ignition timing are also changed to match FLEAN at the same time as the change in FLEAN. As shown, it has become possible to expand the range of FLEAN without causing abnormalities in combustion in the internal combustion engine. Accordingly, engine output can be controlled over a wide range.

Next, a specific processing example of the above-mentioned control is shown in the timing chart of FIG. 11, and the effects of the embodiment will be described.

There is no sudden change in the rotational speed NE before time t1.

Here, if an electrical load such as turning on the air conditioner occurs at time t1, the rotational speed NE starts to decrease due to an increase in the load on the internal combustion engine 1 in the embodiment.

Then, in order to suppress this NE drop, the air-fuel ratio A/F is lowered, the fuel mixture is controlled to be richer, and the output is increased.

Then, in response to the change in A/F, the ignition timing changes to the retarded side, and the injection timing changes to the advanced side. This allows for extremely large changes in A/F. Conversely, when the load decreases, similar control is performed in the reaction direction. Therefore, it can be seen that the change in the rotational speed NE is suppressed to a greater extent than when only the A/F shown by the dotted line is changed. In this way, extremely stable rotation speed control becomes possible.

In the above embodiment, the throttle valve 10 is closed during idling.
There is no so-called idle speed control ISO, which controls the engine speed to the target speed by adjusting the opening or opening/closing of the bypass passage. Capacity can be increased.

[Effects of the Invention] According to the idling control device for an internal combustion engine of the present invention, as the rotation speed changes, the air-fuel ratio is adapted to the air-fuel ratio,
The fuel injection timing and ignition timing are adjusted. As a result,
The air-fuel ratio can be varied over a wide range (for example, 14.
7 to 24), it becomes possible to stabilize the rotational speed during idling.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the basic configuration of the present invention, Fig. 2 is a block diagram showing an embodiment of the invention, Figs. ) and (c) are flowcharts showing the processing performed in this embodiment, in which FIG. 3(a) is a flowchart of the actual fuel injection amount and injection timing calculation routine, and FIG. 3(b) is the injection timing setting routine. 4(a) is a flowchart of the ignition timing calculation routine, FIG. 4(b) is a flowchart of the ignition timing setting routine, FIG. 4(c) is a flowchart of the ignition time matching interrupt routine, and FIG. is a graph corresponding to map 1 of rotation speed NE and lean correction coefficient FLEAN, and Fig. 6 is a graph corresponding to rotation speed NE and ignition timing basic correction value THTBS.
Fig. 7 is a graph corresponding to map 3 of lean correction coefficient FLEAN and ignition timing sub-correction value SUB. Fig. 8 is a graph corresponding to map 3 of lean correction coefficient FLEAN and ignition timing sub-correction value SUB. A three-dimensional graph corresponding to map 4 with the fuel injection timing basic correction value INJBSE, FIG. 9 a graph corresponding to map 5 between the lean correction coefficient FLEAN and the fuel injection timing sub-correction value INJSUB, and FIG. 10 a lean correction coefficient. FIG. 11, which is a graph for comparing possible widths of FLEAN, represents a timing chart showing specific processing of the embodiment. Ml, 1... Internal combustion engine M2... Operating state detection means M3... Air-fuel ratio detection means M4... Fuel supply means M5... Ignition means M6... Idle state determination means Ml... Feedback Control means M8...Air-fuel ratio changing means M9...Supply timing control means MIO...Ignition timing control means 2...Fuel injection valve 4...Lean sensor 6...Electronic control circuit 18... Intake pressure sensor 22...Distributor 24...Rotational speed sensor 26...Igniter 30...Spark plug

Claims (1)

[Scope of Claims] Operating state detection means for detecting the operating state of the internal combustion engine including the engine speed and intake air amount; an air-fuel ratio detection means for detecting an air-fuel ratio; a fuel supply means for supplying an amount of fuel according to an instruction to the internal combustion engine at a time according to the instruction; an ignition means for igniting the internal combustion engine at a time according to the instruction; an idle state determining means for determining whether or not the internal combustion engine is in an idle state based on a detection result of the operating state detecting means; Feedback control means for controlling the actual air-fuel ratio to a target air-fuel ratio exceeding the stoichiometric air-fuel ratio by feedbacking the detected value of the detection means and instructing the fuel supply means to the fuel amount; The time control device further includes air-fuel ratio changing means for changing a target air-fuel ratio used by the feedback control means in accordance with the rotational speed detected by the operating state detection means; supply timing control means for controlling the supply timing of fuel supplied from the fuel supply means according to the detected rotational speed and intake air amount; An idling control device for an internal combustion engine, comprising: ignition timing control means for instructing the ignition means to control ignition timing.