JPS6045748A - Idling speed controller of internal-combustion engine - Google Patents

Abstract

PURPOSE:To improve the traceability and accuracy of an idling speed by switching, under the driving state, the feedback control wherein a motor is driven according to the deviation between the target rpm. and the opening of a throttle valve, so as to move the position of a stopper used to fully close the valve. CONSTITUTION:When an accelerating pedal is released to make a throttle lever 3 come into contact with an actuator rod 5, the rod 5 is grounded via an engine and an idling switch 12 is, therefore, turned on to send a signal to a controller 100. The discriminating unit 132 therein makes judgement of opening feedback control from the signal and makes a changeover switch 131 turned to the side of a control unit 110 from which a signal is to be output. On the other hand, the target throttle opening with respect to the output signal of the cooling water temperature sensor 8 in the target throttle opening map 111 is compared with the actual throttle opening by a comparator 112 and the deviation therebetween is signalled to an opening deviation-to-driving period conversion map memory 113. If the deviation is positive, the driving of an actuator 4 is made in the retractive direction and the driving period thereof is calculated to send the output signal to a selection circuit 130. The voltage signal thereof drives the actuator 4 to displace a throttle valve to the target position. Similarly, the rpm. is made to approach the target value.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an idle speed control device for an internal combustion engine,
In particular, the present invention relates to an idle rotation speed control device for an internal combustion engine that maintains a desired rotation speed by displacing the closing stopper position of a throttle valve using a DC motor.

In engines equipped with a fuel supply device that supplies a so-called air-fuel mixture, which mixes intake air and fuel at the intake pipe gathering point, such as a carburetor, the throttle valve must be opened and closed directly to control the rotational speed during idling. There is a need to. A device is already known that uses a DC motor to displace the fully closed position of a throttle valve, thereby maintaining the rotational speed during idle link.

In such a device, feedback control is performed by detecting the engine rotation speed, comparing it with a target rotation speed, and always maintaining the target rotation speed. However, at low rotation speeds such as during idle link, there is a large time delay until the rotation speed changes even if the slot opening is changed (therefore, engine load such as air conditioner operation may suddenly change due to rotation speed feedback control). In some cases, it was difficult to obtain excellent tracking performance for the engine speed.To improve this, we developed a detector that detects the throttle valve opening by taking advantage of the characteristic that the engine speed corresponds to the throttle opening. Consider a method that provides excellent tracking performance by performing opening feedback control to maintain the target throttle opening.

However, at a small throttle opening such as when idling,
The rate of change in rotational speed relative to opening is large, and it has been difficult to obtain satisfactory rotational speed accuracy using only feedback control based on throttle opening information.

This invention was made to solve these drawbacks, and includes a detector that detects the opening of the throttle valve, a detector that detects the operating state, and an electric motor that moves the stopper position on the fully closed side of the throttle valve. The actuator means is equipped with a rotational speed feedback control for driving the electric motor according to the deviation between the actual rotational speed and the target rotational speed, and an opening control system for driving the electric motor according to the deviation between the actual throttle opening and the target opening. By switching the idling speed feedback control based on the information from the operating state detector and transmitting it to the actuator means, it is possible to obtain an idle link rotation speed with excellent followability of transient response and high rotation speed accuracy. It is an object of the present invention to provide an idle speed control device for an internal combustion engine that is low in cost because the information can be shared and used by other control devices.

Examples of the present invention will be specifically described below.

FIG. 1 is a block diagram of an idle speed control device according to an embodiment of the present invention. 1 is a carburetor of the engine, 2 is a throttle valve provided on the carburetor, 3 is a lever provided on the throttle valve shaft, 4 is an actuator using a DC motor, 5 is an actuator 40 rod; The rotational motion is converted into linear motion via a gear (not shown), and the rod 5 is expanded and contracted. When the driver does not press the accelerator pedal (not shown), the rod 5 contacts the lever 3 of the throttle valve and is at ground potential. It also serves as a switch.

6 is a detector provided coaxially with the throttle valve shaft and detects the valve opening degree, 7 is a rotation speed detection means, 8 is an engine cooling water temperature Ymm temperature detector, 9 is an air conditioner switch, and 10 is an automatic gear shift. 11 is a vehicle speed switch that detects whether the vehicle is running, and 12 is an idle switch that detects whether the vehicle is in an idling state. Reference numeral 100 denotes an idle speed control device, which includes circuit blocks described below.

Reference numeral 110 denotes an opening feedback control section, which further includes a target slot)7v opening degree map storage section 111,
A comparator 112 and a comparator 11 that compare the target opening and the actual throttle opening transmitted from the throttle opening detector 6.
Motor actuator 4 for the opening deviation obtained in 2.
It includes an opening deviation ΔP-driving time T conversion map storage unit 113 that determines the driving time. Next, 120 is a rotation speed feedback control section, which further includes a target rotation speed map storage section 121, a comparator 122 for comparing the target rotation speed and the actual rotation speed transmitted from the rotation speed detection means,
The rotation speed deviation Δ which determines the driving time T of the electric motor actuator with respect to the rotation speed deviation ΔN obtained by the comparator 122
An N-driving time time conversion map storage section 123 is included. 1
30 is an output signal of the opening feedback control section 110;
This is a selection circuit that selects one of the holding modes that is not connected to either of the output signals of the rotational speed feedback control section 120, and includes a changeover switch 131 and an output switching determination section 132 inside. 140 is a drive circuit that receives the output of the selection circuit 130 and sends out a drive voltage for the motor.

FIGS. 2(a) and 2(b) show the contents of the respective target map storage sections, FIG. 2(a) shows the contents of the target throttle opening target map storage section 111, and FIG. It shows the contents of the map storage section 121. In the figure, N
Range and D range indicate the neutral range and drive range of the transmission, respectively, as will be described later.

Figure 3 (al, (bl) shows the contents of the drive time conversion map storage section for each comparison deviation, and Figure 3 (a)
1 shows the contents of the drive time conversion map storage unit 113 for the opening degree deviation, and in the same figure (bl shows the contents of the drive time conversion map storage unit 123 for the rotational speed deviation).

Figures 4(a) to (fl are timing diagrams showing operations when the accelerator is depressed or released;
l is the engine speed, the same figure (bl is the throttle opening, the same figure (
C1 is idle switch information indicating whether the rod 5 is grounded or not (dl indicates the selection status of the selection switch 131), and (e) is the voltage waveform of the opening feedback control unit output terminal. , (f) of the same figure shows the voltage waveform of the output terminal of the rotational speed feedback control section.

Figure 5 (al to (fl) is a timing diagram showing the operation when the air conditioner is turned on and off. The same reference numerals as in Figure 4 indicate the same parts of the timing diagram. FIG. 3 is a timing diagram of voltage signals.

FIG. 6 (al to f) are timing diagrams showing the operation when the gear position of the automatic transmission is switched between the neutral range and the drive range, and the same symbols as in FIG. 4 are
A timing diagram of the same part is shown. Note that FIG. fhl shows a timing diagram of the range switching situation of the automatic transmission.

Next, the operation will be explained.

Fig. 1 shows a carburetor installed in the intake pipe assembly of an internal combustion engine (not shown), and a throttle valve 2 is provided inside, which opens and closes in conjunction with the driver's depression of the accelerator pedal of a vehicle (not shown). do. When the accelerator pedal is depressed, the throttle valve 2 opens accordingly, and as a result, the amount of intake air increases and the amount of fuel supplied also increases. When the engine is operating under no load, this operation increases the rotational speed. Conversely, when the accelerator pedal is released, the slot A/valve 2 is closed by a spring (not shown), the amount of air-fuel mixture supplied decreases, and the engine speed decreases. In order to maintain the so-called idling rotation speed, K needs to supply a suitable amount of air-fuel mixture, and it is necessary to keep the throttle opening at the majority.If it is opened too much, the rotation speed will rise, and if it is closed too much, Rotation speed decreases. In the present invention, a lever 3 is provided on the slot) y valve shaft, and an electric motor actuator 4 is provided facing the lever. When the electric motor is driven, a built-in gear converts rotational motion into linear operation, and a rod 5 is By expanding and contracting the lever 3 and pushing up the lever 3, the idling rotation speed is maintained.

First, the operation under the condition of pressing the accelerator, releasing the accelerator, and pressing the accelerator again in FIG. 4 will be explained.

Assuming that the accelerator pedal is depressed by the driver at time t4□, the throttle valve 2 of the carburetor 1 is opened, and as a result, the lever 3 is activated by the electric motor actuator 40.
Since the robot is separated from the rod 5, the idle switch 12 is in the OFF state. In this case, the output signal of the throttle opening sensor 6 does not correspond to the position of the rod 5 of the electric motor actuator 4, but depends on the amount of depression of the accelerator pedal by the driver, so throttle opening feedback control cannot be performed. , and as a matter of course, rotation speed feedback control cannot be implemented. Therefore, when the idle switch 12 by the rod 5 is in the OFF state, the idle speed control device 100 uses the switching determination section 132 in the selection circuit 130.
It is determined that there is no opening/rotation feedback control, and the selector switch 131 is set to the center holding mode, and no drive signal is sent to the output drive circuit 140, and the rod 5 of the motor actuator 4 is held in the same position. has been done. As shown in FIG. 4, when the accelerator pedal is returned and the lever 3 of the throttle valve 2 comes into contact with the rod 5 of the electric motor actuator 4 at time t4□, the rod 5 is grounded through the engine, and as a result, the idle switch 1
2 is considered to be on, thereby causing the controller 100
sent to. In response to this, the switching determination unit 132 determines that the mode is the opening feedback control mode, and selects the changeover switch 1.
31 to the output signal side of the opening feedback control section 110 as shown in FIG. Target throttle opening information is stored for the output signal of the cooling water temperature detector 8 as shown in FIG. On the other hand, the target throttle opening degrees θ□, θ2, . . . are directly stored in the storage unit as numerical values.

If the output information of the water temperature detector 8 at the current time t4□ is T, i, the optimal target is calculated by interpolation from the target throttle openings θ(Tω2) tθ(Tω3) at the adjacent memory points Tw2 and Tw3. A value θ(Tmi) is calculated and sent to the comparator 112. If the actual throttle opening transmitted from the throttle valve opening detector 6 is θt42, the comparator 112 calculates the deviation θt2−θ( Tmi) is calculated. Now if θt2>θ(Tmi), the opening deviation θ
t2-0(rmi) becomes a positive value, and the result is sent to the opening degree deviation-driving time conversion map storage section 113.

The opening deviation-driving time conversion map storage unit 113 has the ability to compensate for opening deviations at any positive and negative intervals with one correction operation, as shown in FIG. 3(a). The motor drive time required for this is stored.

Therefore, the opening deviation Δθ1−θtJ2− at time t42
θ(r, Ji) is the memory point Δθ2 of the adjacent opening degree deviation. Δ
The optimum driving time τ (Δθi) can be determined by interpolation calculation from the driving times τ (Δθ2) and τ (Δθ3) at the θ arm. As described above, since the opening degree deviation Δθi is the value of the combined pressure, the driving direction is the backward direction and the driving time is calculated as τ(Δθ1). That is, the motor drive time for the opening deviation is determined by a signed calculation, in other words, the motor drive direction (forward or backward direction) and drive time are determined in the conversion map storage section 113.

The output signal of the opening feedback control section 110 shown in FIG. 4 is sent to the selection circuit 130. Selection circuit 130
Since the changeover switch 131 is connected to the output signal side of the opening feedback control section 110 as described above, the voltage signal is transmitted to the motor actuator 4 through the output drive circuit 140, and the motor actuator corresponds to the backward direction. Time driven. As a result, the rod 5 moves backward and moves the throttle valve 2 in the closing direction via the lever 3, displacing it so that it is not close to the target opening. If there is still an opening deviation after this drive, 0.05 After ~0.1 seconds, the comparison is made again and the electric motor actuator is driven.In other words, in the control system of this embodiment, the driving time of the electric motor actuator is determined according to the deviation between the actual opening degree and the target opening degree.
So-called proportional control (P control) operation is adopted.

Now, even if the accelerator is depressed before the idle switch 12 is turned on, if a predetermined period of time has passed since the idle switch 12 was turned on, the engine speed will have settled down to the same level as the throttle valve opening at that time. Therefore, when a predetermined time (td), for example 1 second, has elapsed after turning on, the selection determination unit 132 determines that it is the rotation speed feedback control mode, and switches the selector switch to the rotation speed feedback control section as shown in FIG. 4 (dlK). 120.The target rotation speed map storage section 121 in the one-way rotation speed feedback control section 120 has information as shown in FIG.
A target idle rotation speed is stored for the output signal of the cooling water temperature detector 8.

This target idle rotation speed is stored in the target throttle opening map storage section 111 as shown in FIG.
This value corresponds to the target throttle opening shown in .

The target rotation speed map is calculated at certain intervals with respect to the output signal of the cooling water temperature detector 8.
・The target idle speed is directly stored in numerical value.

Current time tB+T (output signal of water temperature detector 8 of 1 is T
If wi+x, the adjacent memory point Tw2. Tw
Target throttle opening N(τω2)−N(Tω
3), the optimum target value N(Tωi+1) is calculated by interpolation calculation and sent to the comparator 121. If the actual rotational speed detected by the rotational speed detection means 7 is N(t2+T), the comparator 122 calculates the deviation between the actual rotational speed N(t2+T) and the target rotational speed N(Tωi+1), The result is sent to the rotation speed deviation-driving time conversion map storage section 123. As shown in FIG. The optimum driving time for the rotation speed deviation Ni = N(tz+r)-N(Tωi+) at this point is determined by interpolation similarly to the opening deviation-driving time conversion map storage section 113 A voltage signal corresponding to the calculated driving direction and the obtained driving time is sent to the selection circuit 130 at 5 as shown in FIG. 4 if).

Since the changeover switch 131 of the selection circuit 130 is connected to the output signal side of the rotation speed feedback control section 120 at this time, the voltage signal is transmitted to the motor actuator 4 through the drive circuit 140 and driven for a corresponding time. As a result, the rod 5 moves, displacing the throttle valve 2 via the lever 3 and bringing it closer to the target rotational speed.

During idling operation of the engine, it takes about 1 second for K to follow the rotational speed even if the throttle opening is changed. Therefore, after the first correction operation is completed and the throttle opening has changed, and a predetermined period of time, for example, about 1 second, has elapsed, the next rotation speed comparison is performed, and if there is indeed a deviation, the correction operation is performed sequentially. executed.

When the driver depresses the accelerator pedal of the vehicle again at time t113 to open the throttle valve 2, the idle switch constituted by the rod 5 is turned off, and the switching determination section 131 of the selection circuit 130 sets the changeover switch 132 to the hold mode, and the electric motor is switched off. Driving of the actuator 4 is prohibited to keep the rod 5 in the same position.

When the driver releases the accelerator pedal while the vehicle is running and the idle switch is turned on, the engine is driven in the opposite direction by the vehicle and the engine speed no longer corresponds to the throttle valve opening at that time. Therefore, if rotational speed feedback control is performed at this time, problems such as over-tightening or over-opening of the throttle valve will occur. Therefore, information from the vehicle speed switch 11 that detects whether the vehicle is running is transmitted to the selection circuit 130, and when the vehicle is running and the idle switch 12 is in the on state, the opening feedback control of the changeover switch 132 is performed. 110, and executes opening feedback control to maintain the target throttle opening.

Next, the operation when controlling the air conditioner on and off will be explained based on the operation timing chart shown in FIG. Time '51
When the air conditioner switch 9 of the vehicle is turned on, in order to improve the cooling capacity of the air conditioner, it is necessary to increase the idle map rotation speed to a higher value than the original idle map rotation speed.

In the operation example shown in FIG. 5, the air conditioner switch 90 ON information is transmitted to the selection circuit 130 of the control device 100,
31 immediately controls the throttle opening feedback control section 11.
The changeover switch 132 is switched to 0, and opening feedback control is executed.

On the other hand, the target throttle opening map storage unit 111 in the opening feedback control unit 110 receives the ON signal of the air conditioner switch 9, and sets the air conditioner idle map opening θ1 shown in FIG. 2(a) as the target opening to the comparator 112. send to

Before the air conditioner switch 9 is turned on, the throttle opening is such that the target idle speed is achieved, so the target opening θ1 is naturally higher (the data on the difference between the two openings calculated by the comparator 12 is The driving time is sent to the opening deviation-driving time conversion map storage unit 113, and the driving time as shown in FIG. 5 (el) is calculated in the forward direction according to the opening deviation and driving time conversion map shown in FIG. 3(a). The output signal selection circuit 130
send to Since the changeover switch 131 of the selection circuit 130 selects the output signal of the opening feedback control section 110, the drive signal shown in FIG. , extend the rod 5-, and open the throttle opening to reach the target throttle opening via the lever 3. (If there is still an opening deviation after this correction operation, repeat the same procedure again after about 0.1 seconds. A corrective action is performed.If a certain period of time (for example, 1 second) has elapsed since the air conditioner switch 9 was turned on,
Since it can be considered that the rotation has reached the equivalent of the throttle opening set by the opening control, the time t5□ after this time has elapsed.
In this case, the switching determination unit 131 of the selection circuit 130 determines that rotation speed feedback is required, and switches the changeover switch 131 to the rotation speed feedback control unit 120 as shown in FIG. 5(d).
Switch to. As a result, the rotation speed feedback control section 12
0 is a comparator that compares the engine speed at the target opening set by the opening control and the target engine speed N shown in FIG. 122 and sends the rotation speed deviation between the two to the drive time conversion map storage section 123. The rotation speed deviation-driving time conversion map storage section 123 converts the rotation speed deviation into a driving time necessary to compensate for the rotation speed deviation, and sends the voltage signal to the selection circuit 130.

Since the changeover switch 131 of the selection circuit 130 is connected to the rotation speed feedback control section 120 at this time,
The voltage signal is transmitted to the motor actuator 4 through the drive circuit 140 and driven for a corresponding time. As a result, the rod 5 moves, displacing the throttle valve 2 via the lever 3 and bringing it closer to the target rotational speed.

If there is further deviation in rotation speed, the next comparison operation is performed after about 1 second to bring the rotation speed closer to the target rotation speed.

Assuming that the air conditioner switch 9 is turned off at time t55, the opening feedback control is initially carried out in the same way as when it is turned on, and it is assumed that the opening is converged to the target idle opening and the engine speed has settled down to the opening corresponding to the opening at that time. a predetermined period of time,
For example, after one second has elapsed, rotation speed control is performed to eliminate the deviation from the target rotation speed that occurs during opening control.

FIG. 6 shows the idle rotation speed control operation when the automatic transmission of the vehicle is switched to neutral or drive range.

In the drive range, even if the driver does not press the accelerator at all, a so-called creep phenomenon occurs in which the vehicle moves slowly forward. This creep naturally increases as the engine speed increases, causing a shock when switching from neutral to drive range and a feeling of runaway after switching, so the idle speed in the drive range is higher than that in the neutral range. It is common to set it low.

First, suppose that the driver shifts the transmission from the neutral range to the drive range at time t61.
The included range selector switch 1° is shown in Figure 6 (hl
The information changes as follows, and the information is transmitted to the switching determination section 132 of the selection circuit 130. The switching determination unit 132 determines that the opening feedback control is to be performed, and switches the changeover switch 131 to the opening feedback control unit 110. On the other hand, as shown in FIG. 2(a), the target throttle opening map storage section 111 of the opening feedback control section 110 stores the target opening in the drive range, in addition to the neutral range, in response to the output signal of the cooling water temperature detector 8. is memorized,
At time t61, the target throttle opening is calculated and sent to the comparator 112.

The comparator 112 compares the actual throttle opening detected by the throttle opening detector 6 with the target throttle opening, and sends the resulting opening deviation to the drive time conversion map storage section 113. The conversion map storage unit 113 calculates the drive time according to the opening degree deviation, and transmits it to the drive circuit 140 via the changeover switch 131 of the selection circuit 130. As a result, the motor actuator 4 is driven in the correction direction. This opening feedback control is performed for a predetermined period of time, for example, 2 seconds after the transmission range selector switch 10 is reversed.
Executes for seconds. This is because there is a time delay when switching the transmission, and the delay time tends to depend on the ambient temperature, so if you perform rotation speed feedback control immediately after switching, there is a risk of engine stalling, etc. be.

Now, at time t62, when a predetermined period of time has elapsed from time t61, the transmission has already been sufficiently switched, so the changeover determination section 132 determines that rotation speed feedback control is to be performed, and moves the selector switch 131 to the rotation speed feedback control section 120 side. Switch it up.

As shown in FIG. 2(b), the target rotation speed map storage section 121 in the rotation speed feedback control section 120 stores the idle rotation speed for the drive range in addition to the neutral range with respect to the output signal of the cooling water temperature detector 8. Target value is memorized. Note that this target rotational speed and the target throttle opening stored in the target throttle opening map storage section 111 originally correspond to each other.

The method of comparing the calculated target rotation speed at time 162 K with the actual rotation speed using the comparator 122, driving the electric motor actuator 4 for a driving time corresponding to the rotation speed deviation, and executing the rotation speed feedback control has been described above. That's right.

If the transmission is switched from the drive range to the neutral range at Q mJ t 65, opening feedback control is performed to the target opening of the neutral range for a predetermined period of time, and after that predetermined period of time, the rotation speed is changed to the target rotation speed of the neutral range. Performs rotation speed feedback control.

In the above embodiment, the idle speed control device has been explained based on circuit blocks, but a similar idle speed control device can be realized by using a microcomputer and storing a program for performing the above-mentioned control in a storage element. can also obtain the benefits of the present invention.

As described above, the present invention includes a detector for detecting the opening degree of the throttle valve, a detector for detecting the operating state, and an actuator means using an electric motor for displacing the fully closed stopper position of the throttle valve. The operating state detector controls the rotation speed feedback control that drives the motor according to the deviation between the actual rotation speed and the target rotation speed, and the motor feedback control according to the deviation between the actual throttle opening and the target opening. By switching based on the information and transmitting it to the actuator means, it is possible to obtain an idle rotation speed that has excellent followability during load fluctuations of the internal combustion engine and has high rotation speed accuracy. Since the information of the throttle opening degree detector, which is highly useful for many people, can be shared, it is possible to achieve an overall cost-effective system.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an idle speed control device for an internal combustion engine according to an embodiment of the present invention, and FIG. 2 shows the contents of a target map storage section used in the device of the embodiment.
3 shows the target throttle opening map storage section (bl is a water temperature-target value characteristic diagram showing the contents of the target rotation speed map storage section, and FIG. 3 shows the time conversion map storage section used in the same embodiment and example device) (b) is a deviation-driving time characteristic diagram showing the contents of the rotation speed deviation-driving time conversion map storage section; Figure 4 is a timing diagram of the operation of the same embodiment when the accelerator is depressed and released, Figure 5 is an operation timing diagram of the same embodiment when controlling the air conditioner on and off, and Figure 6 is when switching between drive and neutral ranges. An operation timing diagram of the same embodiment is shown. 1... Vaporization!, 2... Throttle valve, 3... Lever, 4... Electric motor actuator, 5... Rod,
6...Throttle opening detector, T...Rotational speed detector, 8...Cooling water temperature detector, 9...Air conditioner switch, 10...Range selection switch, 11...-Vehicle speed Switch, 12...Idle switch, 100...
- Idle rotation speed control device, 110...-Opening feedback control section, 111... Target throttle opening map storage section, 112-... Comparator, 113... Opening degree deviation-
Driving time conversion map storage section, 120--rotation speed feedback control section, 121... target rotation speed map storage section, 122... comparator, 123...-rotation speed deviation-driving time conversion map storage section, 130... selection circuit, 131
-...Changing switch, 132...Output switching judgment unit, 140--Drive circuit 0 Agent Masuo Oiwa Fig. 1 ■1 " Fig. 2 Fig. 00 Fig. 3 (al (b)) Fig. 4 FXJ Fig. 5 6 Figure

Claims (8)

[Claims] (1) A rotation speed means for detecting the rotation speed of the internal combustion engine, a throttle opening detector for detecting the opening of the throttle valve of the carburetor, and an idle detector for detecting the state in which the throttle valve is not depressed. , an idle actuator that determines the closing side stopper position of the throttle valve using a DC motor; a drive direction and drive time of the idle actuator are controlled in response to information from the rotation speed detection means, a throttle opening detector, and an idle detector; In the idle rotation speed control device, the drive time is calculated based on the drive time map stored for the rotation speed deviation between the target rotation speed set in advance and the actual rotation speed obtained by the rotation speed detection means. A numerical feedback control unit calculates the driving time based on the stored driving time map for the opening deviation between the preset target throttle opening and the actual throttle opening obtained from the throttle opening detector. When the internal combustion engine is in the idle state detected by the idle detector and the internal combustion engine is in the idle-link operating state, the throttle opening feedback control section outputs the output signal of the rotation speed feedback control section; In a transient state in which the engine is not in an idling operation state even in the idle state detected by the idle detector, a selection circuit selects the output signal of the throttle opening feedback control section, and the output signal of the selection circuit selects the above-mentioned An idle speed control device for an internal combustion engine that includes a drive unit that drives an idle actuator. (2) a temperature detector that detects the cooling water temperature of the internal combustion engine; a first map that stores the target rotation speed in response to the output signal of the temperature detector; a target rotation speed that corresponds to the output signal of the temperature detector; The idle speed control device for an internal combustion engine according to claim 1, further comprising a second map storing throttle opening degrees. (3) A first map that stores a target rotation speed in response to an air conditioner start switch signal, and a second map that stores a target throttle opening in response to an air conditioner start switch signal. The idle speed control device for an internal combustion engine according to item 1. (4) An idling internal combustion engine according to claim 3, further comprising a selection circuit that receives an air conditioner start switch signal and selects the throttle opening feedback control section for a predetermined period of time after the air conditioner is turned on or off. Rotation speed control device. (5) A first map that receives a transmission neutral or drive range switching signal and stores each target rotation speed for each neutral or drive range, and stores each target throttle opening for each neutral or drive range. An idle speed control device for an internal combustion engine according to claim 1, comprising a stored second map. (6) Claim 1, further comprising a selection circuit that receives a switching signal for the drive or neutral range of the transmission and selects the throttle opening feedback control section for a predetermined period of time after the transmission is switched to the drive or neutral range, respectively. The idle speed control device for an internal combustion engine according to item 5. (7) A selection circuit that switches control from the opening feedback control section to the rotation speed feedback control section after a predetermined period of time has elapsed after transition from the non-idle state detected by the idle detector to the idle state. An idle speed control device for an internal combustion engine according to scope 1. (8) A running detector detects whether the vehicle is running or not, and selects the throttle opening feedback control section when the vehicle is in an idling state as detected by the above-mentioned idle detector and the vehicle is in a running state as detected by the above-mentioned running detector. An idle speed control device for an internal combustion engine according to claim 1, comprising a selection circuit for controlling the idle speed of an internal combustion engine.