JPS6011647A - Engine idle rotational speed control device - Google Patents

Abstract

PURPOSE:To make the effect of engine brake satisfactory, by providing such an opening degree subtracting means that the set opening degree of a throttle valve is gradually reduced upon lowering of load to set a computed opening degree, and as well such an opening degree holding means that, when the computed opening degree reaches a predetermined opening degree, the predetermined opening degree is held as the computed opening degree. CONSTITUTION:A control means 13 in a control unit 15 receives outputs from a throttle valve opening degree sensor 8, an idle switch 9, a lead detectibg means 21 and an engine rotational speed sensor 12, and controls a throttle valve controlling actuator 4 in accordance with the deviation between the actual opening degree of the throttle valve and the desired (idle) opening degree thereof. The control means 13 is connected with an opening degree subtracting means 26 which gradually reduce a first set opening degree to set a computed opening degree upon lowering of load, and an opening degree holding means 27 which holds a second set opening degree when the computed oening degree reaches the second set opening degree which is smaller than the first set opening degree. Further, when the computed opening degree is larger than the desired opening degree, a dashpot control means 24 delivers an opening signal in dependance upon the difference between the computed opening degree and the actual opening degree.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for controlling engine rotational speed (engine rotational speed) when an engine is in an idling operating state.

Conventionally, this type of engine idle speed control device detects engine speed, throttle valve opening, etc., and adjusts the engine speed under relatively stable conditions during idling. A system has been proposed in which, while feedback control (fun roll during idling) is performed, position feedback control of the throttle valve can be performed under conditions where relatively quick control is desired during idling.

However, in such conventional devices, if the opening of the throttle valve suddenly decreases while the opening of the throttle valve is decreasing, a large amount of unburned gas may be generated.
There is a problem that the engine may stall.

On the other hand, when the idle switch is in the closed (on) state, that is, when the accelerator pedal is not depressed and the throttle valve is in contact with the actuator and is under its control, the actuator is gradually retracted and the throttle is It is possible to gradually return the valve to the minimum opening state, but in the second method, the dashpot is operated even when the idle switch is off and the engine is decelerating after reaching a medium load state. It turns out.

However, when decelerating from a medium load condition, unlike when decelerating after a high load condition, a dashpot is not necessary, and by applying the dashpot, the engine braking effect becomes worse. The disadvantage is that fuel efficiency is poor.

That is, from the standpoint of engine braking effectiveness, the dashpot decreasing speed (Δθ/5ec) is increased to increase the starting opening degree θ of the dashbot F. It is desirable to make , small.

On the other hand, in order to reduce the generation of hydrocarbon HC in the exhaust gas discharged from the engine during deceleration,
It is known that it is sufficient to maintain the manifold pressure above a certain pressure.

However, in the conventional dashpot control means, as shown by the broken line in FIG. 7(a), the throttle valve 2 is configured to close during the time width tnp'. As shown, even if the output is below the equal manifold pressure line PL and falls to the region Ar+c where a large amount of hydrocarbon HC is generated, there is a problem in that a large amount of HC is generated.

The present invention attempts to solve these contradictory problems by increasing the effectiveness of engine braking and reducing the generation of hydrocarbons (C) in the exhaust gas emitted from the engine. An object of the present invention is to provide an engine idle speed control device that achieves the following.

For this reason, the engine idle speed control device, which is the first invention of the present invention, is provided so that it can be connected to and detached from the throttle valve provided in the engine intake passage. There is an actuator that engages with the throttle valve to control the opening of the throttle valve, a throttle valve opening detection means that detects the opening of the throttle valve, and the throttle valve is under the control of the actuator. and an idle detection means for detecting that the throttle valve is under the control of the actuator, and when the idle detection means detects that the throttle valve is under the control of the actuator, the actual opening and the target idle opening of the throttle valve are detected. and load detection means for detecting the load state of the engine, and the load detection means detects that the load has decreased from the high load state. and an opening subtraction means for gradually decreasing the first set opening to set the calculated opening, and the opening subtraction means is set when the calculated opening reaches a second set opening that is smaller than the first set opening. The throttle valve controls the actuator by the opening holding means which acts with priority over the opening subtracting means and holds the second set degree as the calculated opening; and the idle detection means. In the state where it detects that it is below.
When the calculated opening degree is larger than the target idle opening degree, the control means gives priority to the target idle opening degree and drives the actuator according to the difference between the calculated opening degree and the actual opening degree. The present invention is characterized in that a control means for transmitting the calculated opening degree is provided.

Further, the engine idle speed control device which is the second invention of the present invention includes a rotation speed detection means for detecting the rotation speed of the engine instead of the opening degree holding means in the first invention of item 1. As soon as the rotation speed detecting means detects that the rotation speed of the engine is similar to the set rotation speed in a state where the calculated opening degree is the 12 setting opening degree, which is smaller than the mi setting opening degree. The present invention is characterized in that an opening holding means is provided which acts preferentially to the opening subtracting means and holds the @22 setting open as the calculated opening.

Furthermore, the engine idle speed control device, which is the third invention of the present invention, is provided so that it can be connected to and detached from a throttle valve provided in an engine intake passage, and the throttle valve is provided at a low opening. an actuator that engages with the throttle valve to control the opening of the throttle valve when the throttle valve is in the range; a throttle valve opening detection means that detects the opening of the throttle valve; and a throttle valve that controls the actuator. and an idle detection means for detecting that the throttle valve is under the control of the actuator, and when the idle detection means detects that the throttle valve is under the control of the actuator, the actual opening of the throttle valve and the target idle opening are detected. a load detection means for detecting the load condition of the engine; and a load detection means for detecting a load reduction from a high load condition. a first opening degree calculation means that gradually decreases the first set opening degree to set a calculated opening degree;
The calculated opening set by the first opening subtracting means is the first opening.
When the second set opening is reached, which is smaller than the set opening, the set time acts preferentially to the first opening subtracting means, and the second opening is reduced to a speed at which the opening is reduced by the first opening subtracting means. a second opening j calculation means for setting the calculated opening by gradually decreasing the opening at a smaller decreasing speed; and the idle detection means.
In a state where it is detected that the throttle valve 1 is under the control of the actuator, the calculated opening degree is 1.
When the opening degree is larger than the target idle opening degree, the calculated opening degree is sent to the control means to drive the actuator according to the difference between the calculated opening degree and the actual opening degree, giving priority to the target idle opening degree. The apparatus is characterized in that it is provided with a control means for sending out the Gutshubot.

Further, the engine idle speed control device according to the fourth aspect of the present invention includes a rotation speed detection means for detecting the rotation speed of the engine, instead of the second opening degree subtraction means in the third invention, and A second opening where the first opening is constant and the calculated opening is smaller than the first set opening.
When the rotation speed detecting means detects that the rotation speed of the engine is equal to or higher than the set rotation speed when the set opening is reached, the second opening subtracting means acts in priority to the first opening subtraction means. The present invention is characterized in that a second opening degree subtraction means is provided for setting the calculated opening degree by gradually decreasing the set opening degree at a decreasing speed lower than the opening degree reduction rate by the first opening degree subtraction means.

Hereinafter, embodiments of the present invention will be explained with reference to the drawings.
1 to 11 show an engine idle speed control device as a first embodiment of the present invention, FIG. 1 is its block diagram, FIG. 2 is its overall configuration diagram, and FIG. 3 is its control procedure. A block diagram showing Fig. 4(a) and t(b) and Fig. 5(
a), (1)), Figures 6 and 7 (a) to (c) are graphs for explaining the effects, and Figures 8 to 11 are flowcharts for explaining the effects. and the first
FIG. 2 is a flowchart for explaining the operation of the engine idle speed control device as a second embodiment of the present invention, and FIGS. Fig. 13 is a block diagram thereof, Figs. 14 and 15 (,) to (c) are graphs for explaining its operation, and Fig. 16 is a graph for explaining its operation. FIG. 17 is a flowchart for explaining the operation of an engine idle speed control device as a fourth embodiment of the present invention.

As shown in FIGS. 1 and 2, in a first embodiment, which is a first embodiment of the present invention, a throttle valve 2 is disposed in an intake passage 1 of an engine E. The pongee 2a is connected to the throttle lever 3 outside the intake passage 1.

Furthermore, when an accelerator pedal (not shown) is depressed, the end portion 3a of the throttle lever 3 moves the throttle valve 2 via the throttle lever 3 in a clockwise direction (ttS2 in the figure).
A wire (not shown) is connected to the throttle valve 2 to rotate it in the opening direction, and a return spring (not shown) is attached to the throttle valve 2 to bias it in the closing direction. ” When the tension of the binary wire is weakened, the throttle valve 2
is starting to close.

By the way, an actuator 4 is provided to control the opening degree of the throttle valve 2 during engine idling operation, and this actuator 4 includes a DC motor (hereinafter simply referred to as "motor") 5 having a ohm 6a on its rotating shaft. The motor 5 has an ohm 6a which is in mesh with an annular ohm wheel 6b.

This worm wheel 6b is integrally provided with a pipe shaft 6c having a female threaded portion 6d.
(a rod having a male threaded portion 7a that is screwed into a female threaded portion 6d of the rod)
'7 is attached to pass through the worm wheel 6b and the pipe shaft 6c.

The tip of the rod 7 comes into contact with the &J portion 3al of the throttle lever 3 via an idle switch 9 serving as idle detection means when the engine E is in an idle operating state.

Here, the idle switch is a switch that is turned on (closed) when the engine is running at idle, and turned off (open) at other times.

Note that an elongated hole 7b is formed in the rod '7, and a pin (not shown) on the actuator body side is inserted into this elongated hole 7b.
is guided, thereby preventing the rod 7 from rotating.

In this way, since the tip of the rod 7 is in contact with the end 3a of the throttle lever 3 when the engine E is in the idle operating state, by rotating the motor 5 in a predetermined direction, the tip of the rod 7 is connected to the pipe shaft through the worm gear. 6c is rotated to cause the rod 7 to protrude (advance) from the actuator 4, the throttle valve 2 is controlled to open, and the motor 5 is rotated in the opposite direction to retract the rod 7 into the actuator 4. (When retracted), the throttle valve 2 is controlled to close by the action of the return spring.

A motor position switch 10 is provided as a position detection means that comes into contact with the rear end of the rod 7, and this motor position switch 10 is turned on when the rod 7 retreats, thereby detecting the position of the rod 7. .

Also, check the opening degree of throttle valve 2 (throttle opening degree).
7- A throttle opening sensor 8 is provided as means for detecting the opening of the throttle valve. As the throttle opening sensor 8, a potentiometer or the like that generates a voltage proportional to the throttle opening is used.

Furthermore, a water temperature sensor 11 that detects a cooling water temperature as a warm-up temperature of the engine E is provided, and a rotation speed sensor 12 that detects the engine rotation speed using an ignition pulse is provided.

Furthermore, a vehicle speed sensor 14 is provided that detects the vehicle speed using a pulse signal having a frequency proportional to the vehicle speed, and a known reed switch is used as the vehicle speed sensor 14.

Further, a pressure sensor 21 is provided as a load detection means for detecting the intake manifold pressure (in this case, an absolute value), which is the engine load, and outputs a signal according to the absolute value of the intake manifold pressure. .

A control means 13 receives detection signals from each sensor 8 to 12, 14, and 21 and outputs a control signal based on these signals to the motor 5 of the actuator 4. Opening degree subtraction 18- Means 23. A control unit (computer) 15 is provided which also serves as a dashpot control means 24 and an opening degree holding means 27.

The control unit 15 performs feedback control of the engine speed based on the signal from the rotation speed sensor 12 under a set condition 1 (described later) when the idle operating state is detected by the idle switch 9 (when the idle switch 9 is turned on). While performing idle speed control), other set conditions when detecting the above idle state ■
(described later), position feedback control of the throttle valve 2 is performed based on a signal from the throttle opening sensor 8.

Here, the above-mentioned condition (3) refers to a case where at least the following items are satisfied, and refers to a condition in which the engine is relatively stable.

(1) A predetermined period of time has elapsed after the idle switch 9 was turned from off to on.

(2) The vehicle speed is extremely low (for example, 2.5 km/h or less).

(3) The deviation of the actual engine rotation speed (actual rotation speed) NR from the target rotation speed NTW is within a predetermined range.

(4) For vehicles equipped with a cooler, a predetermined period of time must have elapsed after the cooler relay, etc. was switched in accordance with the cooler load.

Moreover, the above-mentioned condition (2) refers to a condition in which the above-mentioned condition (2) is not satisfied, the engine is relatively unstable, and it is desired to perform feedback control quickly.

Note that even if either of the above conditions I or TI is satisfied, if it is impossible to control the throttle opening below the minimum throttle opening or above the maximum throttle opening, the control unit 15 will not output an output.

Furthermore, the position (reference position) of the rod 7 of the actuator 4 corresponding to the reference opening degree of the throttle valve 2 (this opening degree is set as a small opening degree corresponding to, for example, an engine rotation speed of around 600 rpm). A motor position switch 10 is provided as a position detection means for detecting. In other words, this motor position switch 1
0 is provided rearward from the rear end surface of the rod 7, and is configured to be turned on (closed) near the most retracted state of the rod 7, and turned off (opened) at other times, and this on/off signal is input to the hunt control unit 15.

Furthermore, as shown in FIG. 3, the control unit 15 receives input from each sensor 8 to 12, 14. It determines the dashpot mode, and also determines the control method, such as whether to perform back control (idle speed control), position feedback control of throttle valve 2, or predictive control. Then, the drive time of the motor 5 (including the determination of the rotational direction) is calculated based on the result of this determination, and a control signal corresponding to this time can be output to the motor 5.

Here, prospective control refers to the following control. That is, under a predetermined operating condition of the engine, for example, the throttle valve 2
21- In order to gradually decrease the throttle valve opening in the case of sudden closing, the rod 7 should be moved to a certain position (
The throttle opening corresponding to this position is called the dashpot opening. ). By doing this, it is possible to gradually reduce the throttle valve 2 from the dashpot opening to the desired opening as the throttle valve is suddenly closed. It can be done. A mode in which such control is performed is a goosepot mode (DP mode).

The control by this hunt roll unit 15 will be explained below.

First, the processing flow for performing this control is, in principle, executed in synchronization with the ignition pulse. In addition, this main 70- is
When there is no ignition pulse, such as when the engine is not operating (when the engine is stalled), it is executed in synchronization with a pseudo pulse signal such as a clock having a predetermined cycle (ΔT).

Note that the above processing flow may be executed in synchronization with a timer interrupt signal (SOms timer interrupt signal) of a certain period (for example, 50m5) in another main 70-.

Now, Figures 8 to 11 include -2 dashpot control.
2= This shows the processing flow of opening control of throttle valve 2,
Terminal a in FIG. 9 is connected to terminal a in FIG. 10, and similarly, terminal d in FIG. 10 is connected to terminal d in FIG. 11. “Return” is the 9th
It is connected to "Return" in the diagram.

When the ignition key is inserted (including the engine starting state), processing flow A in the fan computer 15,
B, T) are started.

Processing flow A is initial setting as shown in FIGS. 8 and 9.

Processing flow B includes determining the dashpot condition, determining the dashpot state, determining whether the idle switch is stable, and determining whether the actual vehicle speed VR is above a predetermined value. The target opening degree PS' inside is gradually subtracted to the predetermined opening degree PTR, and this opening degree P
The process 70-D is for setting the target opening PS' and the target rotation speed NS so that the TR is maintained for the set time To. This is for driving the rod 7 based on the degree PS and the like.

In the process 70-A, as shown in FIGS. 8 and 9, initialization is first performed in block AO, and KS, KT, KP, L, T1 . T2. T3
The contents of ゜MT, . . . are reset and further set to the initial values. ! Next, in block A1, the actual opening PR, actual rotational speed NR, actual vehicle speed VR, cooling water temperature TW, and manifold pressure (
Absolute value) VM and idle switch information ISW are read.

Then, in block A2, a water temperature opening degree PTW, which is a target opening degree, and a water temperature rotational speed NTW, which is a target rotational speed, are set.

As shown in @4 Figures (a) and (b), this set value is a discrete value determined from a map from the cooling water temperature TW, and is determined by an appropriate interpolation method.

In block A3, the dashpot condition is determined, and as shown in FIG. 6 and FIG. 7(a), the throttle opening is determined depending on the magnitude of the manifold pressure and its duration. The starting opening degree of the dashpot is set by PDII.

Further, in block A3, it is determined that the vehicle is in the dashpot state, and each throttle opening degree in the middle of the dashpot is set.

First, the dashpot condition and dashpot state are such that, for example, the actual rotational speed NR is the predetermined rotational speed ND (=10
First, in step a1, it is determined whether the manifold pressure VM is greater than a predetermined pressure α (absolute value).

Then, when VM>α continues longer than the predetermined time β (
Step a2. In step a3), immediately after the dashpot reaches a stable state (K=O), the predictive control start 7 lag KS is set to "1" and the dashpot status flag (dashpot mode established) is set to "1". Reset KT (later opening range #, flow start flag) in step a6), and dashpot condition satisfied 7 lag K
is set to 1 (gutshpot condition satisfied state). (
Step 25 - Step a7) Here, the state in which the dashpot condition is satisfied 7 lag K is on means that the dashpot condition is satisfied if the series of processes A, B, and D are completed and the return is considered as one routine. This only occurs in routines outside the dashpot condition (hereinafter referred to as "routines after the first one"), and the state in which the dashpot state 7 lag KT is on occurs in the routine following the routine in which the dashpot condition is satisfied. (Hereinafter; “2
The following routines are called ``routines after the th routine''. ).

When the VM does not continue for a predetermined time β or more, the dashpot state is canceled (K=0). (Step a12) Also, when VM≦α, the counter (timer) L is reset (Step a8), and if the dashpot condition is satisfied (K=1) (Step a9), the dashpot condition is established. If so, the dashpot state 7 lag KT is turned on (step alO), and a maintenance time TS is set in the dashpot opening degree maintenance counter T3 (step a11), leading to the next block A4.

26-Here, the state in which the maintenance time TS is set in the dashpot opening degree maintenance counter T3 occurs only in the routine immediately after entering the dashpot state (hereinafter referred to as "2nd@th routine j"). It is.

In addition, the dashpot condition is not satisfied (Kl≠1)
If so, the process advances to the next block A4.

Next, in block A4, the idle switch IS
It is determined whether W is in the on state.

That is, if the idle switch SW is on (step a13) and the idle switch flag M1 is off (step a14), the stability determination counter T1 is reset (step a15), and the PFB instruction 7 lag KP is turned on. (Step a16), the idle switch flag MI is turned on. (Step a17) Idle switch ISW is on and idle switch flag M
If T is on, a stability determination counter TO determines whether the idle switch has remained on for longer than a predetermined time γ. (Step a18) Then, in a state where the idle switch ISW is not on for a predetermined period of time γ (T1≦γ), the stability determination counter T1 is incremented by one step a1), and the PFB instruction flag KP is turned on. Furthermore, the idle switch flag MI is turned on.

In addition, the idle switch ISW remains on for a predetermined time γ.
If it continues for a longer time, the idle switch flag M
Turn on l.

If the idle switch TSW is off, immediately reset the idle switch 7 lag MI (step a2).
0), the processing of this block A4 ends.

Next, in block A5, it is determined whether the actual vehicle speed VR is greater than a predetermined vehicle speed VS (=2.5 km/hour) (step a21), and if VR>VS, PFB
Instruction 7 Turn on lag KP. (Step a22) VR
If ≦vS, the process proceeds to the next block B1.

Next, in process 70-B, as shown in FIGS.
The target scheduled opening degree is set in consideration of the dashpot.

First, it is determined by the dashpot condition fulfillment flag K whether the dashpot condition has been established immediately (first routine) (block B1), and if so, the flow advances to block B2.

In block B2, the dashpot opening degree PD1 when the dashpot condition is satisfied [the opening degree θ shown in FIG.
0. Reference] is input to the target opening degree PS'. (Step 1
)1) Next, if the target opening degree PS' is larger than the water temperature opening degree PTW (step b2), that is, when the dashpot condition is satisfied, the dashpot intermediate opening degree holding counter T2 is reset in step b4'. , in step b5, the PFB instruction flag KP is turned on (=1)
Then, block D is reached.

The flow of this process is step bl=b2. bs below [
Process 70-Fb1. It's called J.

In step b2, if PS'≦PTW, step b2 proceeds to step b3, the prospective control start flag KS is reset, and the water temperature opening degree PTW becomes the target opening degree PS'
(step) +4), then block 29
- Leading to D.

If it is not immediately after the dashpot condition is met (first routine), it is determined that the dashpot state (second and subsequent routines) is in the dashpot state (second and subsequent routines) by the dashpot state 7 lag KT (block B3), and the dashpot state (second routine) is determined by the dashpot state 7 lag KT.
If it is determined that the routine is the routine (after the routine), the process advances to block B4.

First, in block B4, it is determined whether the dashpot opening maintenance time T3 has elapsed (step b6), and if it is within the dashbot opening maintenance time T3 (T3>O), the dashpot opening maintenance time T3 is determined. Subtract step b10) from the target opening PS' to the dashpot opening PDI.
Step b11) is set, and then the process goes to block B6.

The flow of this process, step b6. blO, bl 1,
Hereinafter, this will be referred to as "processing flow Fb2J."

If T3≦0, in step b71, the target opening degree PS' is set to the set opening degree PTR [the actual opening degree θ shown in FIG.
□. , corresponds to D], determine whether it is extraordinary or not, and PS
'-30- > If PTR, the target opening P at the dashpot
The held target opening degree PS' is decreased by a predetermined opening degree ΔP so that S' decreases stepwise. (Step b9
) This process flow, step b7. b8. b9 below [
It is called a processing flow Fb3j.

If PS'<PTR, in step b1.2, counter T2 is compared with a predetermined number TO, and if T2>To, counter T2 is preset (step b8), and the target opening degree PS' is set to a predetermined value. Step b9) to subtract the opening degree ΔP, and if T2≦To, the counter T2
(step b9), and further maintain the dashpot intermediate opening PTR at the target opening PS' in step b.
13'') and then reaches block B6.

The flow of this process, step 12. b13 is hereinafter referred to as "processing 7O-Fb4J."

In block B6, if the target opening degree PS' reduced by the predetermined opening degree ΔP is larger than the water temperature opening degree PTW, the PFB instruction flag KP is turned on (step b15
), the operation of subtracting this predetermined opening degree ΔP is repeated.

In block B6, if it is determined that PS'≦PTW, the dashpot state 7 lag KT is reset to end the dashpot control (step b
16), reset the dashpot intermediate opening holding counter T2 (step l+16'), set the water temperature opening PTW to the target opening PS' (block BS), and then proceed to the next block D.

Next, in process 70-D, as shown in FIGS. 8 and 11,
First, in block D1, the idle switch ISW
It is determined whether the idle switch flag MI is on or not.

If the idle switch ISW is on, the rod 7 is driven in block D2 according to dashpot control based on position feedback or control based on rotational speed feedback.

In other words, the actual opening PR is set to the medium opening PM (step cN,), and the PFB instruction 7 lag KP is turned on (KP=1).
If so (step d2), the process proceeds to step d3.

In step d3, a reset is performed to reset the PFB instruction flag KP for each of the series of processes 70-A, B, and D.

Then, the difference ΔP (=P
S-PR) (step d4), and the driving time ΔD of the motor 5 is calculated from the difference AP. (Step d5) Also, if PFB instruction 7 lag KP is off (KP=0) (Step c12), target rotation speed NS and actual rotation speed NR
Calculate the difference ΔN (=MS-NR). (Step d
9) In step d10, the driving time 7ID of the motor 5 is calculated from the difference ΔN.

That is, the driving time ΔD of the motor 5 is calculated from ΔP or ΔN, respectively.

Here, examples of the ΔP-ΔD characteristic and the ΔN-ΔD characteristic are shown in FIGS. 5(a) and 5(b).

Furthermore, it is determined whether setting of each AD is possible 6 (step, :16.dll) 33-Here, in the case of position feedback control (step d6), for example, if 100 m5 has elapsed, it is possible (
YES), otherwise it is determined to be impossible (NO),
In the case of engine speed feedback control (step d
11) for a longer time than in the above case, e.g.
It is determined that it is possible if the person is already inebriated, otherwise it is determined that it is impossible.

In other words, in position feedback control, 100m
Control is possible every 5 intervals, and in engine rotation speed feedback control, control is possible every 700n+s intervals.

Thereafter, in step d7, AD is set in the motor drive timer, and in step d8, the motor 5 is driven when the timer reaches 0.

Note that when AD is positive, the throttle valve 2 is driven to the open side, and when AD is negative, the throttle valve 2 is driven to the open side.
is driven to the closed side.

As a result, the engine is controlled in the target state in both the engine speed feedback control and the position feedback control. In other words, the engine idle speed can be controlled to an optimal state.

In addition, step ci? , d8, NO
If it is determined that this is the case, the motor drive control is not performed and the process returns.

The above processing flow, steps d2 to d8, are hereinafter referred to as “PF
B control processing flow F1".

By the way, if the idle switch ISW is not in the on state (MI=O), first, in step d12,
A reset F of PFB instruction 7 lag KP is performed, and the process proceeds to block D3.

In block D3, it is determined whether the dash board F is in the initial state.

First, it is determined whether the prospective control start flag KS is on, and if it is on, the process proceeds to block D4.

In block D4, rod 7 is the dashpot opening degree
In response to the fact that it has not protruded to I, anticipatory control is performed to extend the front door to this opening degree PD1 by +45.

First, reset S to 7 lag (step d14)
, the process proceeds to step d15.

If the prospective control start flag KS is off, the process returns.

Next, in step cl15, the difference ΔP (=PS' - PM) between the target opening PS' and the intermediate opening PM (for example, the actual opening PR is input) is calculated for prospective control. .

Then, the target opening degree PS' is set to the intermediate opening degree PM (step d16), and the driving time ΔD of the rod 7 is set in accordance with ΔP. (Step d17) And step cl18. d19, step d7. Similarly to d8, the rod 7 is driven by prospective control and then returned.

Note that the processing flow, steps d14 to cl19, will be referred to as [expected control processing flow F2J] hereinafter.

In addition, in the above-mentioned process 70-, a block etc. according to water temperature TW may be added. In this case, the cold idle mode switching slot opening degree P max is set.

In the first embodiment of the present invention, with the above-described configuration, when the engine cooling water temperature TW is low, that is, in the engine cold state (P TW > Pmax) [see symbol G1 in Fig. 4 (, )], the water temperature The opening degree PTW is set. This mode is a cold idle mode.

Also, when the engine is warmed up, (PT
W≦Pmax), the target opening degree (calculated opening degree) PS' according to the dashpot state according to each processing flow A, B, and D
(throttle opening θ, P: first setting opening) and water temperature opening P
A comparison is made with TW (idle opening degree θ□D), and various controls are performed based on this. [Figure 4 (,
)) 1) When the throttle valve 2 is suddenly closed In this case, the throttle valve 2 is suddenly closed, and the engine speed and output under normal driving conditions are suddenly reduced, and especially when the output is It rapidly decreases and falls into the deceleration region (6th
(See symbol UO in the diagram), the idle switch ISW is immediately turned on, and the manifold pressure -37 = force VM rapidly decreases, resulting in a dashpot.6 Once the dashbot mode is established (first routine) In step 70-Fbl, the dashpot opening degree PDI is set to the target opening degree PS'. [
Time t in FIG. 7(,). Reference] and prospective control processing 7
Anticipatory control is performed on the dashpot opening degree PDI by O-F2.

After anticipation control is performed, idle switch l5W (9
) is turned on, and the throttle valve 2 is activated by the actuator 4.
From the moment the dashpot opening is under control, the dashpot opening PDI
Control is also performed based on the dashpot status.

First, in the dashbot opening maintenance state (T3≦0), the throttle opening is maintained at the dashpot opening θ9P for a predetermined time T3 by processing 70-Fb2.
Symbol U1 in FIG. 6 and symbol Q1 in FIG. 7 (,)
Reference], the dashpot opening degree PDI is set to the target opening degree PS'.

38- Then, the target opening PS' is the dashpot intermediate opening PT.
In the subsequent routine until the target opening degree becomes equal to R (second set opening degree), the target opening degree PS' is controlled to gradually decrease at a decreasing rate Δθ/sec by processing 7O-Fb3.

[Symbol U2 in FIG. 6 and symbol Q2 in FIG. 7(a)
Reference 1 Next, the target opening PS' is the dashpot intermediate opening PT.
While it is greater than R, the dashpot intermediate opening holding time tlloI. During this period, the target opening degree PS' is determined by processing 70-F.
By b4, the dashpot intermediate opening degree θl□. 1.

(its calculated value PTR). [Refer to reference numeral U3 in FIG. 6 and reference numeral Q3 in FIG. 7 (,) 1 Here, P
Dashpot intermediate opening P between S'> PTR
The time during which TR is held is represented by tl, nLr+.

Furthermore, the dashpot intermediate opening holding time tlIOLD
After the elapsed time, the target opening PS' becomes the dashpot intermediate opening PT.
From R, by processing 7O-Flli, the decreasing rate Δθ/
It is controlled to gradually decrease in seconds. [Symbol U4 in Fig. 6
and Q4 in FIG.
> PTW).

Then, when the target opening degree PS' becomes equal to the water temperature opening degree PTW, that is, the throttle opening degree θS becomes equal to the idle opening degree θI.
When the engine speed decreases to D, the engine speed and output change along the equal throttle opening curve as shown by reference numeral U5 in FIG. 6, and the state changes to the idle position ID.

Control of the rod 7 in these processes is performed by PFB control process 7O-Fl.

In this way, during the dashpot state time tDP, the engine speed-output characteristic is equal to the manifold pressure line P
The output will not be less than L, and a large amount of hydrocarbon HC will occur in the region A.
The state never shifts to IIc.

ii) When the throttle valve 2 is gradually closed: In this case, the throttle valve 2 is gradually rotated to the closing side, and it takes time for the idle switch ISW to turn on, and the manifold pressure VM gradually decreases. Therefore, dashpots are rarely performed.

However, similarly to the case where the throttle valve 2 is suddenly closed, the anticipation control is performed to the dash-bottom opening degree PD1 by the anticipation control process 7O-F2.

Then, from when the idle switch TSW is turned on and the throttle valve 2 is under the control of the actuator 4, control based on the Gutshubot state is performed from the Gutshubot opening degree PD1.

This process is performed in step 1 of the PFB control process flow.

1ii) In any driving state, depending on whether the cooler switch IAC (20) is turned on or off and the idle switch ISW is turned on or off, the dash board)
The condition occurs intermittently.

As in the above case, the expected control process 7O-F2
Anticipatory control is performed on the dashbot opening PDI.

41- Regarding the dashpot control in the state where the idle switch ISW is on, almost the same operation as in the case where the throttle valve 2 is suddenly closed and the case where the throttle valve 2 is gradually closed is performed.

In each of these states, the rod 7 is controlled to protrude to a larger opening of the water temperature opening PTW or the target opening PS'.

In the second embodiment, which is the second embodiment of the present invention,
As shown in FIG. 12, instead of the process 70-B in the first embodiment, the process 70-0 is the process 70-A.

D, and the series of processing is processing flow A, C, I)
i.e. the ninth
Terminal a in the figure is connected to terminal a in FIG. 12, and terminal d in FIG. 12 is connected to terminal d in FIG. 11, respectively.

Here, processing 7O-Fbl is Fcl, Fb2 is Fc2
In addition, Fb3 corresponds to Fc3, and Fb4 corresponds to Fc4, and they perform similar processing.

That is, in process 70-Fc3, the dashboard 4
2- Target opening PS at decreasing speed Δθ/sec from opening PDI
' is subtracted (step cc9), and after the target opening PS', which is the calculated opening, becomes the dashpot intermediate opening PTR (step cc7), the target opening PS' is maintained at the dashpot intermediate opening PTR. (step ec1.2
, cc13'), PS' = PTR state is NR>
6F continues for Noα, n (see Figure 7 (1)), (e) 1 Then, when NR≦Nl(.0, wa), the decreasing speed Δθ/se from the dashpot intermediate opening PTR (<PDI)
The target opening degree ps' is calculated at step e (step cc 7
, cc 12. cc9), the target opening degree PS' and the water temperature opening degree PTW are compared (block C6), and the larger one is set as the target opening degree PS'. (Blocks C5, C6) Here, each block C1 to C6 is
They correspond to steps 81 to B6 in the first embodiment, and in block C2, steps ec1 to cc5 correspond to steps b1 to b5, respectively, and step b4' is omitted.

Also, in block C4, step cc 6 we
e 7 +cc9-eel Lccl 3' are respectively processed in step b6. b7°~bl 1. bl3', step b1.3 is omitted, and step cc12 is unique to the second embodiment.

Furthermore, step b16' is omitted.

In this manner, in the second embodiment, the opening degree holding of the opening degree holding means 27 is completed by comparing the actual engine speed NR with the dashpot intermediate opening degree PTR, and the sixth embodiment
As shown in the figure, the dashpot can be restarted from a predetermined position Z on the engine speed-output characteristic curve, making it possible to more accurately control the engine speed without impairing the effectiveness of engine braking. .

Note that the other effects of the second embodiment are almost the same as those of the first embodiment.

As shown in FIGS. 13 to 16, in the third embodiment, which is the third embodiment of the present invention, instead of the opening holding means 27 in the first embodiment, the opening subtracting means 23 includes: 1st
A second opening subtraction means 23a, a second opening subtraction means 23b, and a switching means 25 are provided.

That is, the opening subtracting means 23 includes a first controller which receives the throttle opening θ via the control means 13 and outputs the throttle opening in the dashpot state where the throttle valve 2 is in a fast decreasing speed (Δθ+/5ee). Opening degree subtraction means 2.
3a, similarly, the throttle opening θ is controlled via the control means 13.
As a result, the speed of decrease in throttle opening (Δθ2/5ec
) for outputting the throttle opening in the slow dashpot state, and the throttle opening from the first opening subtracting means 23a and the throttle opening from the second opening subtracting means 23I). A switching means 25 for switching and controlling the throttle opening degree is provided.

These decreasing speeds are all speeds of the throttle valve 2 toward the closing side.

The control unit (computer) 15 controls these control means 13. It has the functions of opening subtracting means 23 (first opening subtracting means 23a, second opening subtracting means 23b, and switching means 25) and dashpot control means 24.

In the Pt53 embodiment which is the embodiment of this third invention,
Instead of the process 70-B in the first embodiment, the process 4
5- Row B' is connected to processing flows A and D, and a series of processing is executed by processing flows A, B' and D, that is, terminal a in FIG. Terminal a in the figure, terminal d in Figure 16 is terminal d in Figure 11.
It is designed to be connected to each.

In addition, in FIGS. 13 to 16, the same reference numerals as in FIGS. 1 to 12 indicate substantially the same parts.

Here, processing 70-Fbl' is performed to Fbl, Fcl, Fb
2' is Fb2. Fc2, Fb3' is Fb3. Fc3, Fb4' is Fb4. Each corresponds to Fc4,
Performs the same process as Habo.

That is, in process 70-Fb3', the target opening PS' is reduced from the dash opening PDI at a decreasing speed Δθ, /see.
is subtracted (step b9), and the decreasing speed Δθ2/5ec (<θ
+/5ec), the target opening ps' is subtracted (step b
8. b9. bl 2゜bl 3, bl4, bl 4
), the block B6) compares the opening degree Ps' and the water temperature opening degree PTW, and the larger one is set as the target opening degree Ps'. (Block B5°46-BS) Here, each block B1 to B3. B4', BS, BS
correspond to B1 to B6 in the first embodiment, that is, steps b8, bl4, bl4
' have been added to the first embodiment, respectively, so that while the target opening PS' is greater than the dashpot intermediate opening PTR, and corresponds to the dashpot intermediate opening holding time To in the first embodiment. During the second set opening holding time TO', subtraction is performed from the dashpot intermediate opening PTR every predetermined number of times T'. (Step bi4.b9
) Here, when PS'> PTR, the time during which the target opening PS' is subtracted from the dashpot intermediate opening PTR at a decreasing rate Δθ2/see is expressed as tll0Ln.

In addition, in step b8, the Bricella every predetermined number of times T')
(74=Q) and T4. >Other than T',
While the counter T4 is counted up (step b14'), the target opening PS' in the previous routine is maintained, and the second subtraction speed is compared to the first subtraction speed.
Set late.

Next, if the time becomes tl((H10 or more)(T2
≧To'), the dashpot of the throttle valve 2 is performed again at a decreasing speed Δθ,/sec, and this dashpot is performed while PS'>PTW.

Note that step I)8. bl4. bl4' is omitted, step b9 and block B6 are connected, and target opening degree PS' is set between step b13 and block B6 (p
s'-AP'') may be inserted,
In this case, ΔP' is set smaller than ΔP.

The third embodiment of the present invention achieves substantially the same effects as the first embodiment due to the above-described configuration.

Then, as shown in FIG. 14 and FIG. 15(a),
Engine speed-output characteristic curve (code 03', Q3'
and reference symbols U4' and Q4'), and the effectiveness of the engine brake is higher in the third embodiment than in the first embodiment.

As shown in FIG. 17, in the fourth embodiment, which is the fourth embodiment of the present invention, the process 7 in the first and third embodiments is
Instead of 0-B, B', processing flow C' is processing 70-
A and D are connected, and a series of processes are processing flows A and C'
, D, that is, terminals a1., D in FIG. to terminal a in Fig. 17, the first
Terminal dli in FIG. 7 is connected to terminal d in FIG. 11, respectively.

Here, the processing flow Fcl' is Fbl, Fc1. ,Fb
l', Fc2' is Fb2. Fc2. In Fb2', Fe
3' is Fb3°Fc3. Fb3', Fcb4' is Fb
4. Fc4. Each corresponds to Fb4' and performs the same processing as Fb4'.

That is, in process 70-Fc3', the target opening PS' is reduced from the dash opening PDI at a decreasing speed Δθ, /see.
is subtracted (step cc9), and the decreasing speed Δθ, , /5ee(
<θ, /5ee), the target opening degree PS' is subtracted (step ec7vcc!Lcc1.2-cc'14), and this subtraction continues for N R> Noor, n.

[See FIGS. 15(a) and (b)] And NR≦N1101. l), the target opening P
Compare S' and water temperature opening degree PTW, block B6),
The larger one is set as the target opening degree PS'.

49- (Blocks C5, C6) Here, each block 01 to C3, C4', C5, and C6 correspond to B1 to B6 in the first embodiment, and further correspond to C1 to C6 in the second embodiment. Compatible.

In addition, in FIG. 17, the same symbols as in FIGS. 1 to 16 indicate almost the same things, and the effects of the fourth embodiment are as follows.
This is almost the same as the first to third embodiments.

In this manner, in the fourth embodiment, the second opening degree subtraction means 23
The opening degree subtraction in step 1) is completed by comparing the actual engine speed NR and the dashpot intermediate opening degree PTR, and as shown in FIG. You can restart the dashpot from
It is possible to more accurately control the engine speed without impairing the effectiveness of the engine brake.

Note that switching from the subtraction opening degree in the dashpot to the dashpot intermediate opening degree (maintenance opening degree) may be performed by changing the subtraction time.

Further, as the load detection means, an intake air amount/engine rotation speed (A/N) detector may be used, and the load detection means 50
- The configuration may be such that the throttle opening sensor 8 also functions as a load detection means without providing a stage.

Also, without setting the time setting value β, the single cylinder manifold pressure V
A comparison may be made between M and a predetermined pressure a.

Further, the present device can be applied to both engines having a carburetor type fuel supply system and engines having an injector type fuel supply system.

As detailed above, according to the engine idle speed control device which is the first invention of the present invention, with a simple configuration,
The following effects or advantages can be obtained.

(1) The dashpot can be operated when the engine load is reduced from a high load state, and when the load is reduced from a medium load state, the dashpot is operated only according to the load at that time. I can do it.

(2) When decelerating from a medium load state, engine braking is better applied, contributing to improved safety and improving fuel efficiency.

(3) It is possible to reduce the temporal variation in engine output without impairing the effectiveness of engine braking.

(4) Initial decreasing speed of dashpot (Δθ/
5ee), and the calculated opening becomes the dashpot opening P.
When the dashpot intermediate opening PTR (second setting opening) is smaller than Di (first setting opening), the dashpot opening is temporarily set to a predetermined value (dashpot intermediate opening PTR).
) can be held for a set time To.

(5) The ineffectiveness of engine braking can be significantly reduced, and hydrocarbon HC in exhaust gas discharged from the engine can be reduced.

Further, according to the engine idle speed control device which is the 28th invention of the present invention, there is provided a speed detection means for detecting the speed of the engine, and a second setting in which the calculated opening degree is smaller than the first set opening degree. When the rotation speed detecting means detects that the rotation speed of the engine is equal to or higher than the set rotation speed in the state where the opening degree is reached, the rotation speed detecting means operates in priority over the opening degree subtraction means to determine the second set opening degree. with a simple configuration including an opening holding means for holding the calculated opening as the above-mentioned calculated opening,
1. The effects and advantages of items 1 to 3 and 5 of the first aspect of the present invention can be obtained, and the following effects and advantages can also be obtained.

(1) Initial decreasing speed of dashpot (Δθ/
5ec) is greatly reduced, and the calculated opening is the dashpot opening P.
When the dashpot intermediate opening PTR (second opening) is smaller than Di (first opening), and the engine speed is the set rotational speed N. ol, 9 or more, it is possible to temporarily maintain the opening degree of the dashpot at a predetermined value (dashpot intermediate opening degree PTR).

(2) According to the above-mentioned item 1, it is possible to perform more accurate control.

Furthermore, according to the engine idle speed control device which is the third aspect of the present invention, the calculated opening degree set by the first degree subtraction means becomes a second set opening degree that is smaller than the first set opening degree. and the set time acts preferentially to the first opening subtracting means, and gradually decreases the second set opening at a decreasing speed lower than the decreasing speed of the 153rd opening (opening by opening subtracting means). With a simple configuration in which the second opening degree subtraction means for setting the calculated opening degree is provided, the effects or advantages of items 1 to 3 and 5 in the first aspect of the present invention can be obtained, and further The following effects or advantages can be obtained.

(1) The first decreasing rate at the initial stage of the dashpot (
Aθ1/5ee) is increased, and when the calculated opening becomes the dashpot intermediate opening PTR (second setting opening) which is smaller than the dashpot opening PDI (first setting opening), the first
The second decreasing rate (
Δθ2/5ee), the calculated opening degree can be controlled to decrease during the set time To.

Further, according to the engine idle speed control device which is the fourth aspect of the present invention, the rotation speed detecting means for detecting the engine speed and the calculated opening set by the first opening subtracting means are set by the first opening. When the rotation speed detection means 54-stage detects that the rotation speed of the engine is equal to or higher than the set rotation speed in a state where the second set opening degree is smaller than the first set opening degree, It acts preferentially to the opening degree subtraction means, and gradually decreases the second set opening degree at a rate of decrease that is lower than the rate of decrease in opening degree by the first opening degree subtraction means, thereby setting the two-way operation opening degree. With a simple configuration in which the second opening degree subtraction means is provided, it is possible to obtain the effects or advantages of items 1 to 3 and 5 of the invention of the 1Z opening of the present invention, and furthermore, the following effects or advantages can be obtained. Power C can gain advantages.

(1) The first decreasing rate at the initial stage of the dashpot (
Δθ1/5ee) is increased and the calculated opening becomes the dashpot intermediate opening PTR (second setting opening) which is smaller than the dashpot opening PD1 (first setting opening), and "dual engine" The rotation speed is the set rotation speed NHO1,i)
With this, the calculated opening degree can be controlled to decrease at the second decreasing speed (Δθ2/5ec) which is smaller than the first decreasing speed.

(2) According to the first term above, it is possible to perform accurate control.

[Brief explanation of drawings]

1 to 11 show an engine idle speed control device as a first embodiment of the present invention, FIG. 1 is its block diagram, FIG. 2 is its overall configuration diagram, and FIG. 3 is its control procedure. Block diagrams showing Figure 4 (a), (b), Figure 5
a), (b), Figures 6 and 7 (a) to (c) are graphs for explaining the effects, and Figures 8 to 11 are flowcharts for explaining the effects. 12 is a flowchart for explaining the operation of the engine idle speed control device as a $2 embodiment of the present invention,
13 to 16 show an engine idle speed control device as a third embodiment of the present invention. FIG. 13 is a block diagram thereof, and FIGS. 14 and 15 (a) to (c) are FIG. 16 is a flow chart for explaining the operation, and FIG. 17 is a graph for explaining the operation of the engine idle speed control device according to the fourth embodiment of the present invention. This is a flowchart. 1. Engine intake passage, 2. Throttle valve, 2a.
・Shaft, 3...Throttle lever, 3a...One end of throttle lever, 4...Actuator, 5...Motor, 6a
...Tsohm, 6I)...Tsohm wheel, 6c...
Pipe shaft, 6d... Female threaded part, 7... Rod, 7a...
Male thread part, 7b...Elongated hole, 8...Throttle opening sensor as throttle valve opening detection means, 9...Idle switch as idle detection means, 10.Motor position switch (position sensor) as position detection means ), 11. Working water temperature sensor, 12.. Engine rotation speed sensor, 13.. Control means, 14.. Vehicle speed sensor, 15◆
- Control unit (computer), 21... Manifold pressure sensor as load detection means, 23... Opening degree subtraction means, 23a... First opening degree subtracting means, 23b.
- Second opening degree subtraction means, 24... Dashpot control means, 25... Switching means, 27... Opening degree holding means, E...
engine. Agent Patent Attorney Yoshihiko Iinuma 57 Figure 4 (a) Cooling water temperature rrw0c) Figure 4 (b) Cooling water temperature m'c) - Figure 5 (a) △P (actual opening - target opening → Figure 5 (b) △N (Actual rotation speed - 7th rotation speed) Figure 6 ℃ 1 ver. -〇〇

Claims (4)

[Claims] (1) A throttle valve provided in the engine intake passage,
an actuator that is removably connected to the throttle valve and that engages with the throttle valve to control the opening of the throttle valve when the throttle valve is in a low opening range; A throttle valve opening detection means for detecting the degree of opening of the throttle valve, and an idle detection means for detecting that the throttle valve is under the control of the actuator, and the idle detection means detects that the throttle valve is under the control of the actuator. control means for driving the actuator according to the difference between the actual throttle valve opening and the target idle opening when detecting the engine load; When the detection means detects that the load has decreased from the high load state, the opening subtraction means gradually decreases the first set opening and sets the calculated opening; When the second setting interval is reached, which is smaller than the first opening setting, the setting time acts with priority over the opening subtraction means, and the second opening subtraction means is activated.
When the opening holding means holds the set opening as the calculated opening and the idle detection means detects that the throttle valve is under the control of the actuator, the calculated opening is set to the target idle opening. Dashpot control means for transmitting the calculated opening degree to the control means in order to give priority to the target idle opening degree and drive the actuator according to the difference between the calculated opening degree and the actual opening degree. An engine idle speed control device characterized by being provided with. (2) A throttle valve provided in the engine intake passage;
an actuator that is removably connected to the throttle valve and engages with the throttle valve to control the opening of the throttle valve when the throttle valve is in a low opening range; and an actuator that detects the opening of the throttle valve. and idle detection means for detecting that the throttle valve is under the control of the actuator. a rotational speed detection device that detects the rotational speed of the engine, comprising a control means for driving the actuator according to the difference between the actual opening degree of the throttle valve and the target idle opening degree when the throttle valve is in the lower position; means, a load detection means for detecting the load state of the engine as described in 1. When the load detection means detects that the load has decreased from the high load state, the first set opening degree is gradually decreased by j, and the calculation is performed. An opening subtracting means for setting the opening degree, and an opening subtraction means for determining that the rotation speed of the engine is equal to or higher than the set rotation speed when the calculated opening degree reaches a second set opening degree that is smaller than the first set opening degree. When the rotation speed detecting means detects the rotation speed, it acts in priority over the opening degree subtracting means.
When the opening holding means holds the second set opening as the calculated opening and the idle detection means detects that the throttle valve is under the control of the actuator, the calculated opening is set to the Target eye 3 - When the idle opening is higher than the idle opening, the calculated opening is sent to the control means to drive the actuator in accordance with the difference between the calculated opening and the actual opening, giving priority to the target idle opening. An engine idle speed control device, characterized in that it is provided with dashpot control means for sending out. (3) A throttle valve provided in the engine intake passage;
an actuator that is removably connected to the throttle valve and that engages with the throttle valve to control the opening of the throttle valve when the throttle valve is in a low opening range; and an actuator that detects the opening of the throttle valve. and an idle detection means for detecting that the throttle valve is under the control of the actuator, and the idle detection means detects that the throttle valve is under the control of the actuator. load detection means for detecting the load state of the engine, comprising a control means for driving the actuator according to the difference between the actual opening of the throttle valve and the target idle opening; and 4- a first opening subtraction means that sets a calculated opening by gradually decreasing the first set opening when the same load detection means detects that the load has decreased from a high load state; When the calculated opening set by the first opening subtraction means reaches a second set opening, which is smaller than the first set opening, the set time acts with priority over the first opening subtracting means. 2 Setting opening degree” 1.
The throttle valve is under the control of the actuator by the second opening subtracting means that gradually decreases the opening at a decreasing speed lower than the opening decreasing speed by the opening subtracting means and setting the calculated opening, and the idle detecting means. When the calculated opening degree is much lighter than the target idle opening degree, the actuator is activated in accordance with the difference between the calculated opening degree and the actual opening degree, giving priority to the target idle opening degree. An engine idle speed control device, comprising dashpot control means for sending the calculated opening degree to the control means for driving. (4) a throttle valve provided in the engine intake passage;
an actuator that is removably connected to the throttle valve and that engages with the throttle valve to control the opening of the throttle valve when the throttle valve is in a low opening range; and an idle detection means for detecting that the throttle valve is under the control of the actuator, and the idle detection means detects that the throttle valve is under the control of the actuator. rotational speed detection means for detecting the rotational speed of the engine, comprising a control means for driving the actuator according to the difference between the actual opening degree of the throttle valve and the target idle opening degree when detecting the rotational speed of the engine; A load detecting means for detecting the load state of the engine; and a first set opening for setting a calculated opening by gradually decreasing a first set opening when the load detecting means detects that the load has decreased from a high load state. When the first opening degree subtraction means and the first opening degree subtraction means set the calculated opening degree to a second set opening degree, which is smaller than the first set opening degree, the rotational speed of the engine is equal to or higher than the set rotational speed. When the rotational speed detecting means detects that a second opening subtraction means for setting the calculated opening by gradually decreasing the opening at a decreasing speed smaller than the lower speed; and an idle detection means described in -I-.
In a state where it is detected that the throttle valve is under the control of the actuator, if the calculated opening is significantly higher than the target idle opening, the calculated opening is given priority over the target idle opening. to the control means to drive the actuator 1 according to the difference between the actual opening degree and the actual opening degree.
An engine idle speed control device, characterized in that it is provided with a dashpot control means for sending out a double calculated opening.