JPH0454820B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an idle speed control device for an internal combustion engine used in an automobile or the like.

[Conventional technology]

Generally, in a car, the engine speed is compared with the target idle speed when the engine is idling, and the throttle valve opening is changed according to the deviation to control the engine speed to the target speed, thereby reducing fuel consumption when the car is idling. Some vehicles are equipped with an idle speed control device designed to achieve this.

Fig. 2 shows a conventional device of this kind, in which 1 is a piston, 2 is a cylinder, 3 is an intake valve, 4 is an exhaust valve, and 5 is a cylinder.
is an exhaust pipe, 6 is a three-way catalytic converter, 7 is an intake pipe, 8 is a throttle valve, and on the upstream side of the throttle valve 8 there is a bench lily 9 and an air cleaner 10.
is provided, and the fuel in the float chamber 11 is sucked in through the main fuel passage 12 when the intake air taken in through the air cleaner 10 passes through the bench lily 9, is atomized, and becomes a mixture with the intake air. is introduced into the cylinder 2 via the throttle valve 8 and the intake pipe 7. In this case, the main fuel passage 12
A main air bleed 13 is provided in the middle of the
The fuel in the float chamber 11 is atomized and atomized by intake air from a main air bleed passage 14 provided upstream of the bench lily 9. on the other hand,
The idle port 15 is located downstream of the throttle valve 8.
A slow air bleed passage 16 is provided on the upstream side of the bench lily 9, and the fuel in the main fuel passage 12 is supplied to the slow air bleed passage 1.
Slow air bleed due to intake air from 6 17
The particles are finely divided and discharged from the idle port 15. As a result, fuel is secured during idling when the throttle valve 8 is approximately fully closed. In this case, the amount of fuel discharged from the idle port 15 is
8. Here, throttle valve 8
is connected to the accelerator pedal (not shown), and when driving, the opening degree corresponds to the amount of depression of the accelerator pedal, and when the accelerator pedal is released and the vehicle is idling, the opening degree is the amount necessary to maintain the idling state. Become. Further, this throttle valve 8 is provided with a lever 19 on its rotating shaft.
By rotating 9 with the actuator 20, the opening degree at idle can be varied.

Next, the configuration of the idle rotation speed control system will be explained. The actuator 20 consists of a DC motor 21 and a gear mechanism 22. The gear mechanism 22 converts the rotational movement of the DC motor 21 into a linear movement of a plunger 23, and this linear movement causes the lever 19 to move.
is driven to vary the opening degree of the throttle valve 8. A forward rotation control pulse U and a reverse rotation control pulse D having a predetermined pulse width are applied to the DC motor 21 from a control circuit 30. In this case, an idle switch 24 is provided in the actuator 20, which is turned on (closed) when the tip of the plunger 23 is in contact with the lever 19, that is, when the accelerator pedal is released and the engine is idle. Further, 25 is a rotation speed detector that detects the engine rotation speed, and here, an ignition coil 26
A rotation pulse signal having a period corresponding to the engine rotation speed N is extracted from the connection point between the engine breaker 27 and the interrupter 27. 28
is an air conditioner operation start switch (hereinafter abbreviated as A/C SW), which is one of the engine loads, 29
32 is a gear shift switch that detects that the transmission (not shown) is in the neutral position or that the clutch (not shown) is turned on (depressed), that is, that the engine and wheels are disconnected; 32 is the engine cooling switch; water 3
A temperature detector 30 detects the temperature of 1, an idle switch 24 that detects the idle state, a rotation speed detector 25, an A/C/SW 28, and a speed change switch 29.
This is a control circuit that controls the opening degree of the throttle valve during idling based on the output signal of the temperature detector 32, and performs control to converge the engine speed to the target rotation speed _N0 . As shown in FIG. 3, the control circuit 30 includes an arithmetic processing unit (hereinafter abbreviated as CPU) 300 and a read-on memory (hereinafter abbreviated as ROM) that stores programs, constants, etc. for controlling the idle rotation speed. ) 301 and a random access memory (hereinafter abbreviated as RAM) 3 that stores results during calculations, etc.
02, and an interface circuit (hereinafter abbreviated as IFC) 303 for transmitting and receiving signals between the various switches described above and the actuator 20.

Next, the operation of the above configuration will be explained using the flowcharts of FIGS. 4 and 6. First, when the engine is started, the CPU 300 executes the processing shown in FIG. 4 according to the program stored in the ROM 301. That is, the CPU 300 takes in the output signal from the rotation detector 25 and measures the period of the signal to detect the current engine rotation speed N (step 100), and then takes in the output signal from the temperature detector 32. Detect the current cooling water temperature TW (step 101). In this case, the output signal of the temperature sensor 32 is
After being converted into a digital signal by the IFC 303, it is taken into the CPU 300. After this, CPU30
0, in step 102, the target rotational speed _N0 during idling is calculated. The target rotational speed _N0 during idling differs depending on the cooling water temperature TW, and also differs when the air conditioner as a load is in an operating state and in a non-operating state, and has, for example, the characteristics shown in Fig. 7. ing. This idle target rotation speed N ₀ is previously stored in the ROM 301 as a constant, and therefore its calculation is realized by reading this constant from the ROM 301. Next, the CPU 300 is the engine speed N
In step 103, it is determined whether or not N is 400 RPM or more. If N is less than 400 RPM, it is determined that the engine is before a complete explosion. In step 117, the drive mode of the actuator 20 is set to hold mode, and the idle rotation for the actuator 20 is Does not perform any numerical control. However, if N is 400 RPM or more, it is determined that the engine has completely exploded, and in step 104, it is determined whether the shift switch 29 is on, that is, whether the transmission is in the neutral position or whether the clutch is on. The determination is made based on the output signal of the switch 29, and in step 105 it is determined whether the idle switch 24 is on. As a result, the gear change switch 29
If it is off, it is assumed that the vehicle is running and the drive mode is set to hold mode in step 117.Also, even if the gear shift switch 29 is on, if the idle switch 24 is off, the accelerator pedal is not pressed. Assuming that an operation by the driver has been added, the drive mode is set to the hold mode in step 117, and idle rotation speed control for the actuator 20 is not executed in either case.

However, if the speed change switch 29 is on (neutral state or clutch-on state) and the idle switch 24 is on, it is assumed that the main fuel to the engine is being supplied from the idle port 15, that is, the engine is in an idle state, and step 106 is performed.
It is determined whether the A/C SW 28 has changed from on to off or from off to on. As a result, if there is no change in the A/C SW 28, the deviation (absolute value) between the idle target rotation speed N ₀ and the current engine rotation speed N is determined in step 107, and whether or not this deviation is larger than a predetermined value ΔN _D is determined. If it is smaller, the drive mode of the actuator 20 is set to the hold mode in step 117. However, if the deviation is larger than the predetermined value _ΔND , idle speed control measures are performed in steps 108 to 112 to converge the engine speed N to the target speed _N0 . That is, step
At 108, the current engine speed N and target speed N ₀
If N ₀ > N, it is necessary to control the opening of the throttle valve 8 to the open side, so the drive mode of the actuator 20 is set to the open side mode (step 109), and conversely, if N ₀ <N In this case, since it is necessary to control the opening degree of the throttle valve 8 to the closing side, the drive mode of the actuator 20 is set to the closing side mode (step 110). After this, step
At step 111, drive time data Pw of the actuator 20 corresponding to the deviation N ₀ -N is read from the ROM 301 . The relationship between this Pw and N ₀ −N is, for example, the 8th
As shown in the figure, the relationship is established such that as N ₀ -N or N - N ₀ increases, Pw also increases almost proportionally. In this way, when the drive time data Pw of the actuator 20 corresponding to the deviation between the idle target rotation speed N ₀ and the current engine rotation speed N is obtained, the CPU
300 causes the IFC 303 to generate a forward rotation control pulse U or a reverse rotation control pulse D for driving the actuator 20 in a direction corresponding to the drive mode for a time corresponding to Pw in step 112. In this case, when the drive mode is on the open side, a forward rotation control pulse U is generated, and on the contrary, when the drive mode is on the close side, a reverse rotation control pulse D is generated. As a result, the throttle valve 8 is set at the target rotation speed during idling.
Setting control is performed in the direction corresponding to N ₀ , and the engine rotation speed N comes to converge to the target rotation speed N ₀ . Thereafter, the CPU 300 repeats the process from step 100 onwards, and after a certain hold time T _H has elapsed, generates a control pulse corresponding to the change in the rotational speed at that time.

As mentioned above, the target rotation speed N ₀ and the engine rotation speed N
The engine rotational speed N is maintained at the target rotational speed N0 by controlling the opening of the throttle valve 8 in accordance with the deviation from the engine rotational speed _N0 . However, A/C.
If SW 28 changes from on to off or from off to on, CPU 300 detects this change in step 106. Furthermore, it is detected in step 113 whether or not this change is a change in the A/C SW 28 from on to off. If the change is in the on state, the drive mode of the actuator 20 is set to the open side drive mode (step 113). 114), and if the change is to the off state, the closed side drive mode is set (step 115). Then, in the next step 116, a rotation speed change due to an increase or decrease in engine load due to the start or stop of operation of the air conditioner is anticipated, and drive time data P _WAC of the actuator 20 corresponding to this expected load change is read from the ROM 301. put out. After this, in step 112 the data is
A forward rotation control pulse U or a reverse rotation control pulse D for driving the actuator 20 in a direction corresponding to the drive mode for a time corresponding to P _WAC .
Generated from IFC303. As a result, the opening degree of the throttle valve 8 is opened by the opening degree corresponding to the drive time data P _WAC when the air conditioner starts operating.
Conversely, when the operation is stopped, it closes by the opening degree corresponding to the data P _WAC . After performing such predictive control, the CPU 300 adjusts the idle rotation speed to the target rotation speed through feedback control in steps 100 to 112.
Converge to N ₀ .

Further, the pulse drive control process in step 112 is configured as shown in the flowchart of FIG. 6, and the actuator 20 is driven after waiting for the completion of a predetermined hold time _TH . That is,
In step 201, the CPU 300 detects whether or not a predetermined hold time T _H has been completed. If it has not been completed, the CPU 300 repeatedly executes the processing of steps 100 to 112 in FIG. 4. When the CPU 300 detects completion of the predetermined hold time T _H , the CPU 300 determines whether or not it is in the hold mode in step 202.
If you are in hold mode, follow steps 100~ in Figure 4.
Repeat process 112. If it is not the hold mode, the drive time data is set in the timer register in the RAM 302 in step 203, and the drive mode is set to the open side drive mode or the close side drive mode in the next step 204. After this, in step 205, IFC303
From then on, generation of a forward rotation control pulse U or a reverse rotation control pulse D corresponding to the drive mode is started. Then, it is detected whether the generation time of the control pulse U or D has been completed, that is, whether the driving time of the actuator 20 has reached the time corresponding to the driving time data. After stopping the generation of D and setting a predetermined hold time T _H in the timer register in the next step 206, the drive mode is set to hold (step 207), and the process proceeds to step 100 in FIG. As a result, during idle rotation speed control using feedback control, the actuator 2
0 is driven intermittently by a control pulse having a rest time of a predetermined hold time T _H , and the engine rotation speed N is converged to the target rotation speed N ₀ .

FIG. 9 shows a time chart of the forward rotation control pulse U and the reverse rotation control pulse D when the A/C switch 28 changes from OFF to ON, for example.

[Problem that the invention seeks to solve]

However, in the above-mentioned conventional device, the rotation speed during idling is controlled even when the engine is cold, that is, when the cooling water temperature TW is low, and therefore the opening degree of the throttle valve 8, which can be variably controlled by the actuator 20, is The range is considerably larger than the range of the opening degree of the throttle valve 8 during idling, which is required after the engine is warmed up. Therefore, A/C・SW2
When the actuator 20 is repeatedly driven to the open side by an abnormal output signal from a load condition detector such as 8, the throttle valve 8 opens to the opening degree corresponding to the mechanical upper limit position of the actuator 20, and the engine speed decreases. increases abnormally and is dangerous. For example, due to the difference in driving capacity between the forward rotation direction and the reverse rotation direction of the electric motor 21, when the actuator 20 is driven to the opening side for a time corresponding to the driving time data P _WAC , the opening degree will change to the driving time when the actuator 20 is driven to the closing side. If the opening degree is greater than the closing degree when driven for the time corresponding to the data P _WAC , A/
If the C/SW 28 is turned on and off frequently, the actuator 20 is driven alternately to the open side and the close side for the time corresponding to the drive time data P _WAC , so the difference between the opening degree to open and the degree to close to closing increases. As a result, the throttle valve 8 gradually opens and finally opens to an opening corresponding to the mechanical upper limit position of the actuator 20, and the engine speed rises to near the maximum allowable speed, especially after the engine is warmed up. In addition, in the conventional device, the position of the plunger 23 when the engine is stopped remains at the position immediately before the engine stopped, so when the engine is started when the engine is cold, the throttle valve 8 is not opened to the opening degree necessary for starting. If so, there is a problem that it is difficult to start or cannot be started.

The present invention has been made to solve the above-mentioned problems, and provides an idle speed control device that improves starting performance when the engine is cold and can prevent abnormal increases in engine speed. The purpose is to obtain.

[Means for solving problems]

The idle speed control device according to the present invention includes a speed detecting means for detecting the engine speed, a temperature detecting means for detecting the engine temperature, an idle state detecting means for detecting the idle state of the engine, and a throttle speed during idling. An actuator that variably controls the valve opening, a position detection means that detects a predetermined reference position of the drive position of the actuator, a load state detection means that detects the operating state of the engine load, and a target rotation speed that is set based on the engine temperature. target rotation speed setting means for
A complete explosion detection means for detecting a complete engine explosion, a first control pulse for setting the throttle valve opening to the above-mentioned reference position before a complete engine explosion, and starting operation of an engine load during idling after an engine complete explosion. Or a second control pulse to increase or decrease the throttle valve opening by a predetermined amount when the engine is stopped, and an intermittent feedback to make the engine speed converge to the target speed other than when the engine load changes when the engine is idling after the engine has completely exploded. a control means for generating control pulses and driving the actuator with each of these control pulses; and a control means for generating a second control pulse when the drive position of the actuator is on the opening side from the reference position when the engine is idling after a complete explosion; The device is equipped with means for inhibiting the feedback control pulse and generating intermittent feedback control pulses.

[Effect]

In the present invention, before the engine complete explosion, the actuator is driven to set the throttle valve opening to the opening corresponding to the above reference position, and when there is no change in the engine load when the engine is idling after the engine complete explosion, or when the current throttle valve opening is If the valve opening is on the open side from the above reference position, the actuator is driven by an intermittent feedback control pulse to converge the engine speed to the target speed determined according to the engine temperature, and the engine is completely exploded. If there is a change in engine load during subsequent idling and the current throttle valve opening is closer to the closing side than the reference position, the actuator is activated by a control pulse to increase or decrease the throttle valve opening by a predetermined amount. to drive.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, those indicated by symbols 1 to 29, 31, and 32 are the same as those of the prior art. Further, a position detection switch (hereinafter abbreviated as HI/SW) 33 for the plunger 23 that turns off (opens) when the opening degree of the throttle valve 8 exceeds the opening degree corresponding to a predetermined reference position is provided in the actuator 20. There is. In addition,
The position of the plunger 23 where the HI/SW 33 is switched from on to off is hereinafter referred to as the High side reference position. This High side reference position is set near the upper limit opening of the throttle valve 8 during idling after the engine has been warmed up. The control circuit 30 also detects an idle state. Idle switch 24, rotation speed detector 25,
Based on the output signals of A/C SW 28, speed change switch 29, temperature detector 32 and HI SW 33,
The opening degree of the throttle valve 8 during idling and starting is controlled to converge the engine rotation speed to the target rotation speed N ₀ and to improve startability when the engine is cold. The control circuit 30, as shown in FIG.
CPU300, ROM301, RAM302 and
It is composed of IFC303.

Next, the operation of the above configuration will be explained using the flowcharts of FIGS. 5 and 6. First, when the engine is started, the CPU 300 executes the process shown in FIG. 5 according to the program stored in the ROM 301. In steps 100 to 117, processing similar to the conventional method is performed. That is, in step 100, the engine rotation speed N is detected, in step 101, the cooling water temperature TW is detected, and in step 102, the target rotation speed _N0 as shown in FIG. 7 is detected. Next, the engine speed N is
It is determined in step 103 whether or not the N is 400 RPM or more, and if N is less than 400 RPM, it is determined that the engine is before complete explosion, and in steps 118 to 120, the opening degree of the throttle valve 8 is adjusted to the opening degree corresponding to the high side reference position. Set the drive mode of actuator 20 to HI/SW to set
The opening side drive mode or the closing side drive mode is set depending on the on/off state of 33. That is, CPU
300 detects the on/off state of the HI/SW 33 in step 118, and if it is on, the plunger 2
Since the current position of No. 3 is closer to the closing side than the High side reference opening degree, the drive mode of the actuator 20 is set to the opening side (step 119). Conversely, if it is in the off state, the current position of the plunger 23 is
Since it is on the open side from the High side reference position, the drive mode of the actuator 20 is set to the close side (step 120). After this, the CPU 300 stores the predetermined drive time data P _WO in the ROM in step 121.
301, and in the next step 112, a forward rotation control pulse U or a reverse rotation control pulse D for driving the actuator 20 in the direction corresponding to the drive mode for a time corresponding to _PWO is sent to the IFC 303.
Generate from. As a result, the opening degree of the throttle valve 8 before the engine complete explosion is set to the opening degree corresponding to the High side reference position of the plunger 23. That is, the throttle opening degree before the engine is completely exploded is at least the opening degree corresponding to the Hhgh side reference position of the plunger 23, which improves starting performance when the engine is cold.

On the other hand, if the engine speed N is 400 RPM or more, it is determined that the engine has completely exploded, and as in the past, it is determined in step 104 whether the gear change switch 29 is on or not, and step 104 is performed.
In step 105, it is determined whether the idle switch 24 is on. As a result, when the speed change switch 29 is off and when the idle switch 24 is off, the drive mode is set to the hold mode in step 117, and idle rotation speed control for the actuator 20 is not executed in either case. However, if the speed change switch 29 is on (neutral state or clutch-on state) and the idle switch 24 is on, the current position of the plunger 23 is determined to be on the open side or close side of the High side reference position in the next step 122. What is there?
Detected by the on/off state of HI/SW33,
If it is on the open side than the High side reference position, that is
If HI/SW33 is off, follow the steps below.
106, 113 to 116 A/C/SW 28 changes from on to off or from off to on, no predictive control is performed, and in steps 107 to 112, the engine speed N converges to the target speed _N0 . Performs rotation speed control processing. That is, when the current position of the plunger 23 is on the open side rather than the High side reference position, anticipatory control is prohibited when the A/C SW 28 changes from on to off or from off to on. Therefore, for example, the actuator 2
If the opening degree when the actuator 20 is driven to the opening side for a time corresponding to the driving time data P _WAC is larger than the opening degree to close when the actuator 20 is driven to the closing side for a time corresponding to P _WAC , A/
C. If SW28 is turned on and off frequently, P _WAC
Since the actuator 20 is driven alternately to the opening side and the closing side for a time corresponding to Since the throttle valve 8 does not open more than the opening corresponding to the high side reference position set near the upper limit opening of the throttle valve 8 when the machine is idling, there is no abnormal increase in the engine speed N and it is safe. On the other hand, if it is determined in step 122 that the current position of the plunger 23 is closer to the closing side than the High side reference opening, that is, HI/SW3
3 is on, step 106 turns on the A/C.
It is determined whether the SW 28 has changed from on to off or from off to on. As a result, A/C・
If there is no change in the state of the SW 28, in steps 107 to 112, idle speed control processing is performed to converge the engine speed N to the target speed _N0 , as in the conventional case. or,
If the A/C SW 28 changes from on to off or from off to on, proceed to step 113 as before.
Prospective control is performed at ~116 and 112. After the CPU 300 performs such predictive control, the CPU 300 executes step 100.
The idle speed converges to the target speed through feedback control that reaches ~112.

Incidentally, the pulse drive control processing in step 112 is performed as in the conventional art as shown in the flowchart of FIG. 6, and the actuator 20 is driven after waiting for the completion of a predetermined hold time _TH . Furthermore, when the engine speed N is less than 400 RPM, the actuator 20 is driven in the direction of the High side reference position.
For example, when the current position of the plunger 23 is closer to the close side than the High side reference position and the current position of the plunger 23 reaches the High side reference position due to the opening side drive, the HI/SW 33 is turned off and step 120
The drive mode of the actuator 20 is switched to the closing drive mode. After this, the pulse drive control shown in FIG. 6 is executed, but the plunger 23
Since the current position of has reached the High side reference position and the drive mode has been switched to the close side drive mode, the CPU 300 operates the actuator 20 to throttle the throttle valve 8 for the time corresponding to the drive time data _PWO in steps 203 to 205. is driven in the closing direction.
Therefore, the current position of the plunger 23 returns to the closed side from the High side reference position. However, at this time, the HI SW 33 switches from OFF to ON, so the drive mode of the actuator 20 is set to the open side mode again in step 119 of FIG. 5, and the CPU
300 is the driving time data P _WO in steps 203 to 205.
The actuator 20 is driven in the direction in which the throttle valve 8 opens for a time corresponding to the time. As a result of repeated execution of such processing, the position of the plunger 23 swings around the High side reference position. That is,
When the engine speed N is less than 400 RPM, the opening degree of the throttle valve 8 is set to the opening degree corresponding to the High side reference position.

As described above, according to this embodiment, the opening degree of the throttle valve 8 at the time of starting is set to the opening degree corresponding to the High side reference position, which is set near the upper limit opening degree of the throttle valve 8 at the time of idling after the engine is warmed up. Since this is set, it is possible to improve starting performance when the engine is cold. or,
Even if the throttle valve 8 is repeatedly opened due to predictive control at the time of load change due to an abnormal output signal from the load condition detector such as when the A/C SW 28 is repeatedly turned on and off, the opening side will be lower than the high side reference position. Since this anticipatory control is prohibited, the throttle valve 8 will not open beyond the opening degree corresponding to the High side reference position, so it is safe.

In the above embodiment, whether or not the throttle valve opening has reached the reference value is detected based on the output of the HI/SW 33, but the slider rotating shaft of the variable resistor is connected to the rotating shaft of the throttle valve 8. However, it may be determined whether the opening degree of the throttle valve 8 has reached the reference value based on a resistance value or a voltage value accompanying a change in the valve opening degree. Further, although the explanation has been given using an air conditioner as an example of the engine load, the present invention can be similarly implemented in the case of power steering, etc. Furthermore, the engine speed N is
A complete explosion state is detected by detecting an abnormality at 400 RPM, but a complete explosion may also be detected based on a complete explosion signal output from the alternator.

〔Effect of the invention〕

In the present invention, the opening degree of the throttle valve is controlled to a predetermined reference position before the engine completely explodes, so that a sufficient throttle opening degree can be obtained even when the engine is started when the engine is cold. It is possible to improve starting performance when the engine is cold. In addition, if the throttle opening is on the open side from the reference position when the engine is idling after a complete explosion, anticipatory control when the engine load changes is prohibited, and even if the load state detection means outputs an abnormal signal, the engine Abnormal increases in rotational speed can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the device of the present invention, FIGS. 2 and 3 are the overall block diagram and control circuit block diagram of the conventional device, respectively, and FIGS. 4 and 6 are flowcharts showing the operation of the conventional device. , Fig. 5 is a flowchart showing the operation of the device of the present invention, Fig. 7 is a characteristic diagram of the target rotation speed, Fig. 8 is a characteristic diagram of actuator driving time, and Fig. 9 is a diagram showing the characteristics of the actuator when it starts operating. This is a time chart of the control pulses. 8... Throttle valve, 20... Actuator, 24... Idle switch, 25... Rotation speed detector, 28... Operation start switch, 30... Control circuit, 32... Temperature detector, 33... Position detection Switch. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A rotation speed detection means for detecting the rotation speed of the engine;
temperature detection means for detecting the temperature of the engine; target rotation speed setting means for setting the idle target rotation speed in response to the detection force of the temperature detection means; complete explosion detection means for detecting complete explosion of the engine; an actuator for variable control of the throttle valve opening of the engine, a position detection means for detecting a predetermined reference position of the drive position of the actuator, an idle state detection means for detecting an idle state of the engine, and an engine operated when the engine is idle. A load state detection means for detecting the operating state of the load; and a first control pulse for setting the throttle valve opening to the reference position before the engine complete explosion in response to the detection force of each of the detection means; A second control pulse for increasing or decreasing the throttle valve opening by a predetermined amount when the engine load starts or stops when the engine is idling after a complete explosion, and the engine speed when the engine load changes when the engine is idling after a complete explosion. a control means that generates intermittent feedback control pulses to converge the engine speed to a target rotation speed, and drives an actuator using these control pulses; When it is on the open side of
1. An idle speed control device for an internal combustion engine, comprising means for prohibiting generation of control pulses and generating intermittent feedback control pulses.