JPS6011646A - Engine idle rotational speed control device - Google Patents

Abstract

PURPOSE:To make the effect of engine brake satisfactory, by providing such an arrangement that the set opening degree of a throttle valve is gradually reduced upon lowering of load to hold a computed opening degree, and as well desrease in the computed opening degree is controlled in accordance with the result of comparation with a predetermined 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 detecting means 21 such as, for example, an intake-air pressure sensor, etc. 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 having first and second opening degree subtracting means 23a, 23b which deliver the opening degrees of the throttle valve in a dashpot condition in which the opening degree of the throttle valve decreases at a fast rate and as well as in a dashpot condition in which the same decreases at a slow rate. Further, when a computed opening degree obtained by the subtracting means 26 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 an 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. While performing feedback control (idle speed control), a system has been proposed in which the throttle valve is able to perform body-shrinking feedback control under conditions where relatively quick control is desired during idling operation.

However, with such conventional devices, when the opening of the throttle valve is reduced sharply, there is a problem that a large amount of unburned gas is generated or the engine stalls. There is a point.

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 with this method, the dashpot cannot be operated even when the idle switch is off and the engine is decelerating after reaching a medium load state. become.

3- However, when decelerating from a medium load state, unlike when decelerating after a high load state, a dashpot is not necessary, and by applying a dashpot,
The drawback is that engine braking is less effective, and fuel efficiency is also poor.

In other words, from the standpoint of engine braking effectiveness, it is desirable to increase the dashpot decreasing speed (Δθ/5ec) and decrease the dashpot starting opening degree θDP. From the perspective of vehicle body shock caused by torque fluctuations due to A/F fluctuations, the dashpot decreasing speed (Δθ/see') is reduced,
It is desirable to increase the starting opening degree θDP of the dashpot.

However, in the conventional dashpot control means, as shown in FIG. 6(a), the throttle valve is returned to the idle opening degree θ1'D at a constant speed in a time @t pp.
The drawback is that the engine brake is not very effective, and the shock to the car body is also large.

41 The present invention attempts to solve these contradictory problems, and provides an engine idle speed control device that can increase the effectiveness of engine braking and reduce the shock generated to the engine body. The purpose is to

For this reason, the engine idle speed control device 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. an actuator that engages with and controls the opening of the throttle valve; a throttle valve opening detection means that detects the opening of the throttle valve;
1. 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 load detection means for detecting a load state 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 load detection means detects that the load has decreased from the high load state, the first set opening degree is gradually decreased and held as the calculated opening degree, and the calculated opening degree is changed to the first set opening degree. When the calculated opening is larger than the second set opening, the speed at which the calculated opening is reduced is increased, and when the calculated opening is smaller than the second set opening, the speed at which the calculated opening is decreased is controlled to be slow. the target idle opening when the calculated opening is larger than the target idle opening in a state where the idle detection means detects that the throttle valve is under the control of the actuator; Dashpot control means is provided which sends the calculated opening degree to the control means in order to drive the actuator according to the difference between the calculated opening degree and the actual opening degree. .

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. Block diagrams showing the functions of the chair cards, Figures 4 (a), (b), 56-1m (a), (b), Figures 6 (a), (b), and Figure 7. Graphs for 8th to 1st
1 is a flowchart for explaining the operation thereof, and FIG. 12 is a flowchart for explaining the operation of the engine idle speed control device as a second embodiment of the present invention.

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

Furthermore, when an accelerator pedal (not shown) is depressed, the end 3a of the throttle lever 3 rotates the throttle valve 2 in the clockwise direction (opening direction) in FIG. 2 via the throttle lever 3. A wire (not shown) is connected to the throttle valve 2, and a return spring (not shown) is attached to the throttle valve 2 to bias it in the closing direction.
When the tensile force of the wire 1 is weakened, the throttle valve 2 closes.

Incidentally, an actuator 4 is provided to control the opening degree of the throttle valve 2 during engine idling operation.This actuator 4 is a DC motor (hereinafter simply referred to as "motor") having a ohm 6a on its rotating shaft. 5, and this ohm 6a with the motor 5 meshes with an annular worm wheel 6b.

This ohm wheel 6b is integrally provided with a pipe shaft 6c having a female screw portion 6d.
A rod 7 having a male threaded portion 7a screwed into a female threaded portion 6d is attached to the rod 7 passing through the ohm wheel 6b and the pipe shaft 6C.

The tip of the rod 7 comes into contact with an end 3ak 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 the rod 7 is formed with an elongated hole 7b, and a bottle (not shown) on the actuator main body side is guided in this elongated hole 7b, so that the rod 713
− It is designed to prevent rotation.

Above this, the tip of the lock Y7 is located at the end 3a of the throttle lever 3 when the engine E is in an idling state.
Therefore, when the motor 5 is rotated in a predetermined direction, the pipe shaft 6C is rotated via the ohm gear, and the rod 7 is protruded (advanced) from the actuator 4, so that the throttle valve 2 opens. When the motor 5 is rotated in the opposite direction to retract (retract) the rod y 7 into the actuator 4, 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.

Further, a throttle opening sensor 8 is provided as a throttle valve opening detection means for detecting the opening of the throttle valve 2 (throttle opening). A potentiometer or the like that generates a proportional voltage 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. A mount roll unit (computer) 15 is provided which also functions as a dashpot control means 24 and an opening degree subtraction means 26.

This opening) calculation means 26 receives the throttle opening θ via the control means 13 and inputs the decreasing speed () of the throttle valve 2
1st IIF 1 degree subtraction means 23 that outputs the throttle opening degree in the dashpot state where ΔθI/5ec) is fast;
Similarly to a, in response to the throttle opening θ via the control means 13, the decreasing speed of the throttle opening (Aθ2/5ec)
a second opening i computation means 23b that outputs the throttle opening in the slow dashpot state, and t51.
(opening degree) throttle opening degree from the computation means 23a and @
A switching means 25 for switching and controlling the throttle opening from the second opening subtracting means 2311 is provided.

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

The engine speed control unit 15 performs feedback control of the engine speed based on a signal from the speed sensor 12 under a set condition 1 (described later) when the idle state is detected by the idle switch 9 (when the idle switch 9 is turned on). (idle speed control), while 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, "condition 1" 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) Vehicle speed is extremely low (e.g. 2.SLtm/h or less)
To be.

(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 when the above-mentioned condition 1 is not satisfied, the engine is relatively unstable, and quick feedback control is desired.

Note that even if either of the above-mentioned conditions I or IT 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.

Further, the position of the rod 7 of the actuator 4 (the reference position ) A motor position switch 10 is provided as a position detection means for detecting the position. That is, this motor position switch 10 is provided rearward from the rear end surface of the rod 7,
The rod 7 is configured to be on (closed) near the most retracted state and off (open) at other times, and this on/off signal is input to the control unit 15.

Furthermore, as shown in Figure @3, the hunt roll unit 15 receives input from each sensor 8 to 12, 14. , the dashboard mode is determined, and the control method is determined, such as whether to perform feedback control of the engine speed (idle speed control), position feedback control of the throttle valve 2, or predictive control. Then, depending on this determination result, the drive time of the motor 5 (including determination of the rotational direction) is calculated, and a control signal corresponding to this time is 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
When the throttle valve opening is suddenly closed, the throttle valve opening should be gradually reduced by adjusting the lock Y7 to a certain position (the throttle opening corresponding to this position is called the dashpot opening). By doing this, the throttle valve 2 can be gradually decreased from the dashpot opening to the desired opening as the throttle valve is rapidly closed.

A mode in which such control is performed is a dash board F mode (DP mode).

14- The control by this control 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), the process is performed in synchronization with a pseudo pulse signal such as a clock having a predetermined cycle (ΔT).

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

Now, FIGS. 8 to 11 show the processing flow of the opening degree control of the throttle valve 2 including the Gutshu bond control.
Terminal a in the figure is connected to terminal a in Figure 10, and similarly,
The terminals d in FIG. 10 are connected to the terminals d in FIG. 11, respectively, and "return-1" in FIG. 11 is connected to "return" in @9.

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

Processing 70-A is initialization as shown in FIGS. 8 and 9.

The process 70-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 equal to or higher than a predetermined value. Gradually subtract the opening degree and set the target opening PS (however, if the target opening PS is greater than the set opening PTR, increase the subtraction speed and set PS<P
If it is TR, the subtraction speed is set small) and the target rotation speed NS is set. Processing flow D is as follows.
As shown in FIGS. 8 and 11, this is for driving the rod 7 based on the target opening degree PS, etc.

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 ゜M I, . . . are reset and further set to the initial values.

Next, in block A1, the actual opening PR, actual rotational speed NR, actual single speed VR, cooling water temperature TW, and manifold pressure (
Absolute value) VM and idle switch information TSW 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.

This setting value is as shown in Fig. 4 (a), (1)).
It is a discrete value calculated from a map based on the cooling water temperature TW, and is determined by an appropriate interpolation method.

In block A3, the gutshu pot condition is determined, and as shown in FIG. 6 (1)) and FIG. 7, 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 to PDI.

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 (=17
- 1.00 Orpm), and first, in step a1, it is determined whether the manifold pressure VM is greater than a predetermined pressure a (absolute value).

Then, when VM>α continues for longer than the predetermined time β, step a2. In a3), if the dashpot has just reached a stable state (K=O), the predictive control start 7 lag KS is set to "1" and step a4. as), reset the dashpot status flag (flag for opening subtraction flow start after dashpot mode 1' is established), step &6), and dashpot condition satisfied 7 lag K
is set to 1 (dashpot condition satisfied state). (
Step a7) Here, the state in which the dashpot condition fulfillment 7 lag K is on means that the dashpot condition is satisfied, assuming that the series of processes A, B, and D are completed and the return is one routine. (hereinafter referred to as the "first and subsequent routines"), the state in which the dashpot status flag KT is on occurs in the routine following the routine in which the dashpot condition is satisfied (18). Hereinafter, this will be referred to as the "second and subsequent routines" and will occur only in the following routines.

If the VM does not continue for a predetermined period of time β, the dashpot state is canceled (K=O). (Step a12)
In addition, when VM≦α, the counter (timer) L is reset (step a8), and if the dashpot condition is satisfied (K=1) (step a9), the dashpot state is established. As, dashpot state 7
The lag KT is turned on (step a10), and the dashpot status flag T3 is further turned on (=1), step 1), leading to the next block A4.

Here, the state in which the dashpot state flag T3 is on occurs only in the routine immediately after the dashpot state (hereinafter referred to as "second routine-1").

In addition, the dashpot condition is not satisfied (11≠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 ISW is on (step a13) and the idle switch flag MI is off (step a14), the stability determination counter T1 is reset (step a15), and the PFB instruction flag KP is turned on (step a15). a16) Turn on the idle switch flag MI. (Step a17) Idle switch ISW is on and idle switch flag M
If the idle switch is on, a stability determination counter T1 determines whether the on state of the idle switch continues 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 in step a19.
), turn on PFB instruction 7 lag KP, and then turn on idle switch flag MI.

In addition, the idle switch ISW remains on for a predetermined time γ.
If it continues for a longer time, the idle switch 7 lag M
Turn on T.

If the idle switch TSW is off, the idle switch flag MT is immediately reset (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 the predetermined vehicle speed VS (=2.51 nn/hour) (step a21), and if VR>VS, PF
Turn on the B instruction flag KP. (Step a22) V
If R≦VS, the process proceeds to the next block B1.

Next, in process 70-B, as shown in FIG. 8.10,
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 PDI (opening degree θ shown in FIG. 6(b)
np) is input to the target opening PS. (Step bi
-)21- When the target opening degree PS is larger than the water temperature opening degree PTW (step I) 2), that is, when the dashpot condition is satisfied, the PFB instruction flag KP is turned on (=1) in step b5. , and then reaches block D.

The flow of this process, steps l) 1, 112, and b5, will be referred to as "process 7O-FclJ" hereinafter.

In step b2, if PS≦PTW, step b2 leads to step b3, and prospective control starts with 7 lags K
S is reset, water temperature opening degree PTW is set to target opening degree PS (step b4), and then block D is reached.

If it is not immediately after the dashpot condition is met (first routine), does the dashpot status flag KT indicate that it is in the dashpot status (second and subsequent routines)? lJ is determined (block B3), and it is determined that the dashpot state (second and subsequent routines) is established.
This leads to block B4.

First, in block B4, it is determined whether the state has just entered the dashpot state (step 1) 6), and if the state has just entered the dashbot state (T3-1), that is, if the second routine , step biO) to reset the dashpot state 7 lag T3, step 1) to set the target opening degree PS to the dashpot opening degree PD1, and then proceed to block B6.

The flow of this process, step b6. b10. b11 is hereinafter referred to as [Processing 70-Fc2j.

If T3-0, in step l)7, the target opening ps is set to the set opening PTR [actual opening θT shown in FIG. 6(b)].
PS≧
If it is PTR, the counter T2 is preset (20) in step b8, and the target opening PS at the dashpot is set.
The target opening PS that was maintained so that it decreases in a stepwise manner
is increased by a predetermined opening degree ΔP. (Step 1] 9)
The flow of this process, step b7. b8. b9 below [
This is called a processing flow Fc3J.

If PS<PTR, the counter T2 is compared with a predetermined number To in step I]12, and if T2>To, the counter T2 is preset (step)]8), and the target opening PS is set to a predetermined value. Step b9) to subtract the opening degree ΔP, and if T2≦TO, add the counter T2 and further maintain the target opening PS in step b1
3), then proceed to block B6.

The flow of this process, step b12. Ir13 is hereinafter referred to as “
It is called process 70-Fc4J.

In block B6, if the target opening PS reduced by the predetermined opening AP is greater than the water temperature opening PTW,
Turn on PFB instruction 7 lag KP (step b15)
, the operation of subtracting the predetermined opening degree ΔP is repeated.

In block B6, if it is determined that PS≦PTW,
In order to end the dashpot control, the dashpot status flag KT is reset (step b1
6), set the water temperature opening degree PTW to the target opening degree PS (block BS), and then proceed to the next block D.

Next, in the processing pro D, as shown in FIGS. 8 and 11,
First, in block D1, idle switch TSW
It is determined whether the idle switch flag Ml is on or not.

If the idle switch TSW is on, the rod 7 is driven in block D2 in accordance with the position feedback-based goose spot control or the rotation speed feedback control.

That is, if the actual opening PR is set to the intermediate opening PM (step di), and the PFB instruction flag KP is on (KP=1) (step d2), the process proceeds to step d3.

In step d3, a reset is performed to reset the PFB instruction 7 lag 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 ΔP. (Step d5) If the PFB instruction 7 lag KP is off (KP=O) (step d2), the difference ΔN (=NS-NR) between the target rotational speed NS and the actual rotational speed NR is calculated. (Step d9
) In step dlo, the driving time ΔD of the motor 5 is calculated from the difference ΔN.

That is, the driving time ΔD of the motor 5 is calculated from AP 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 each ΔD can be set. (Steps d6 and d11.) Here, in the case of position feedback control (step d6), it is determined that it is possible (YES) if, for example, 100 m5 has elapsed, otherwise it is determined that it is impossible (NO), and the engine rotation speed is determined to be In the case of feedback control (step d11), it is determined that it is possible if a longer time than in the above case, for example, 700 m5 has elapsed, and otherwise it is determined that it is impossible.

In other words, in position feedback control, Loom
Control is possible every s interval, and in engine rotation speed feedback control, control is possible every 700m5 interval.

Then, in step d7, ΔD is set to 2 for motor drive.
6- Set the timer, and in step d8, the timer is set to 0.
The motor 5 is driven by the main motor.

Note that when ΔD 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.

This allows the engine to be controlled in a targeted state in both engine rotational speed feedback control and position feedback control. In other words, the engine idle speed can be controlled to an optimal state.

In addition, step c! 7. In any of d8, NO
If it is determined that this is the case, the motor drive control is not performed and the process returns.

” The flow of the two series of processes, steps d2 to d8, will be described below as [P
This is called FB control processing 7O-FIJ.

By the way, if the idle switch ISW is not in the on state (MT=O), first, in step d12, the PFB instruction flag KP is reset, and the process proceeds to block D3.

In block D3, it is determined whether the dashpot 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 the rod 7 has not protruded to the opening degree PD1, anticipatory control is performed to cause the rod 7 to protrude to the opening degree PD1.

First, reset the 7-lag KS (step d14),
The process proceeds to step d15.

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

Next, in step d15, the difference ΔP (=PS-PM) between the target opening degree PS and the intermediate opening degree PM (for example, the actual opening degree PR is input) is calculated for prospective control.

Then, the target opening degree PS is set to the intermediate opening degree PM (step 616), and the drive time ΔD of the lock Y7 is set in accordance with ΔP. (Step d17) Then, in steps d1B and d19, step d7.
Similarly to d8, the rod 7 is driven by anticipation control and then returned.

Note that the process flow, steps d14 to cl19, will be referred to as "expected control processing 7O-F2J" hereinafter.

In addition, in the above-mentioned process flow, a block etc. according to water temperature TW may be added. In this case, the cold idle mode switching slot opening degree Pmax 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(a)], the water temperature The opening degree PTW is set. This mode is a cold aisle mode.

Mainly, while the engine is warmed up (P
TW≦Pmax), by each process 70-A, B, and D,
Target opening degree PS and water temperature opening degree P according to dashpot status
A comparison is made with TW, and each control is performed based on this comparison. [See symbol G2 in Figure 4(a)]i
) When the throttle valve 2 is suddenly closed 29- In this case, the throttle valve 2 is suddenly closed, the idle switch ISW is immediately turned on, and the manifold pressure VM is rapidly reduced, resulting in a dashpot.

[Refer to symbols Qi and Q2 in FIG. 6(b)] When the dashbot mode is established (first routine), the dashpot opening PDI is changed to the target opening PS by processing 7O-Fc1. Settings are made. [Time t in FIG. 6(b). Refer to] Then, by the prospective control process 7O-F2, prospective control is performed on the dashpot opening degree PD1.

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 degree PD1 is under the control of
Control is also performed based on the dashpot status.

First, immediately after the dashpot state (second routine), the gunshot pot opening degree PD1 is set to the target opening degree PS in process 70-Fe2.

30- Then, in the third and subsequent routines, the target opening P
S is determined by processing 70-Fc3 to reduce the rate of decrease Δθt/
It is controlled to gradually decrease in seconds. [See time Qllt, a and time t1 in FIG. 6 (1)] Furthermore, when the target opening degree PS becomes smaller than the set opening degree PTR, the decreasing speed Δθ2/! 3
It is controlled to gradually decrease with ee (<Δθl/5ee).

[Refer to time tb in Fig. 6 (1) 1 In this way, the dashpot at the decreasing speed Δθ2/see is maintained while the dashpot state 7 lag KT is established (that is, while pS>PTW) , executed.

The control of the rod 7 in this process is performed by the PFB control process 7.
Performed by O-Fl.

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 SW to turn on, and the manifold pressure VM gradually decreases. Therefore, dashpots are rarely performed.

However, in the same way as when the long throttle valve 2 is suddenly closed,
The dashpot opening degree P is determined by the prospective control process 7O-F2.
Expected control is performed to D1.

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

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

1ii) In any operating state, the dashpot state occurs intermittently depending on whether the cooler switch IAC (20) is turned on or off and the idle switch ISW is turned on or off.

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

Dashpot control in a state where the idle switch SW is on is performed in substantially the same manner as when the throttle valve 2 is suddenly closed and when the throttle valve 2 is gradually closed.

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 of the present invention, instead of the process flow B in the first embodiment, as shown in FIG.
c are connected to the processing ports o-A and D, that is, the terminals a1. is connected to terminal a in FIG. 12, and terminal d in FIG. 12 is connected to terminal d in FIG. 11, respectively, so that the dashbot opening degree PD1
The target planned opening degree Ps1 is subtracted from the target opening degree Ps1 at a decreasing speed Δθ+/sec (step c8), and the dashbot opening degree PD2 (
<PDI) to decrease speed Δθ2/5ee(<Δθ1/5
ec), the target planned opening PS2 is subtracted (step 09
~c12), target planned opening degree PS1 and target planned opening degree PS2
Compare step c15), the larger is the target opening P
It is set as s. (Step c1
6. ci 7) Here, each block c1 to c6 is! 1
) corresponds to B1 to B6 in the k1 embodiment, and in block c2, steps 01 to c5 correspond to steps b1 to b5, respectively.
Steps cl' and c6 are unique to the second embodiment.

Also, in block C4, step c7. ci3゜c14 are steps b 6 , l) 10 , +
111, and in block C5, step c19. c21 and b16. Similarly, step c22 corresponds to block B5.
In this case, step c23 corresponds to step 1)15.

Further, step c20 is to preset the counter T2.

Note that steps c9 to ci2 are omitted and the target scheduled opening degree PS2 is set (PSi, -) between c8 and step c15.
ΔP′) may be performed. in this case,
The reduction value ΔP' can be set to any value smaller than ΔP, and the ratio of the reduction speed can also be set more finely.

In this way, in the second embodiment, the first opening calculation means 23a and the second opening calculation means 23b calculate independently, and the target scheduled opening is larger among the calculated values. 3
4 degrees can be selected by the switching means 25, and in the second embodiment, substantially the same effects as in the first embodiment can be obtained.

Note that the decreasing speed may be switched depending on the subtraction time.

Further, as the load detection means, an intake air amount/engine speed (A/N) detector may be used, and the throttle opening sensor 8 has a function corresponding to the load detection means without providing the load detection means. It may also be configured to function as both.

Also, without setting the time set value β, simply manifold pressure VM
It is also possible to compare the predetermined pressure α with the predetermined pressure α.

Furthermore, 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 described in detail above, according to the engine idle speed control device of the present invention, the throttle valve provided in the engine intake passage is provided so as to be removable from the throttle valve, and the throttle valve is connected to and detachable from the throttle valve provided in the engine intake passage. an actuator that engages with the throttle valve at a certain time to control the opening of the throttle valve; and a throttle valve opening detection means 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 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 state of the engine, and a load detection means for detecting the load state of the engine, and a load detection means for detecting that the load has decreased from a high load state. The first set opening degree is gradually decreased and held as the calculated opening degree, and when the calculated opening degree is larger than the second set opening degree, which is smaller than the first set opening degree, the calculated opening degree decreases. an opening subtraction means for increasing the speed and controlling the speed at which the calculated opening is reduced when the calculated opening is smaller than the $2 set opening; When the calculated opening degree is greater than the target idle opening degree in a state where it is detected that the actuator is under control, "1"
Dashpot control means is provided for sending the calculated opening degree to the control means in order 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. With a simple configuration, the following effects and advantages can be obtained.

(1) When the engine load is reduced from a high load state, by operating the dashpot, when the load is reduced from a medium load state, the current load can be reduced.
Only 51Z can activate Dashboard F.

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

(3) The temporal variation in engine output can be kept small without impairing the effectiveness of engine braking.

(4) Initial decreasing speed of dashpot (Δθ/
5ec) can be increased, and the decreasing rate (Δθ/5ee) of the goose spot after the middle period can be decreased.

37-(5) According to item 4, the effectiveness of engine braking can be increased, and the shock generated on the engine body can be reduced.

(6) The area indicated by the symbol Sa in FIG. 6 can be enlarged, thereby preventing the engine from stalling.

[Brief explanation of the drawing]

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), Figure 6 (a), (b) - Figure 7 are all graphs to explain the effect, and Figures 8 to 11 are all flowcharts to explain the effect. Yes, 12th
The figure is a flow chart for explaining the operation of an engine idle speed control device as a second embodiment of the present invention. 1. Engine intake passage, 2. Throttle valve, 28'
1+ axis, 311+ throttle lever, 3a11 image throttle lever one end, 4...actuator, 5...motor, 38- 6a...two ohms, 6b...two ohms wheel, 6c...
・Pipe shaft, 6d... Female threaded part, 7... Rod, 7a.
・Male thread part, 7b...Elongated hole, 8...Throttle opening sensor as means for detecting throttle valve opening, 9...Idle switch as means for detecting idle, 10...Motor position switch (position detecting means) 5 sensor), 11...Water temperature sensor, 12...Engine speed sensor, 13...Control means, 14...Vehicle speed sensor, 15
...Control unit) (computer), 21...
Manifold pressure sensor as load detection means, 23a.
・First opening subtraction means, 23b: Second opening subtraction means, 24: Dashpot control means, 2S: Switching means, 26: Opening subtraction means, E: Engine. Agent Patent Attorney Yoshihiko Iinuma Figure 4 (0) Cooling water temperature TW (t') - Figure 4 (b) Cooling water temperature TW ('c) - Figure 5 (a) ΔP (actual opening - target opening) Figure 5 (b) △N (Actual rotation speed - Target rotation speed) Figure 6 (a) (b) ↑a City Time t-4

Claims (1)

[Scope of Claims] A throttle valve provided in an engine intake passage is provided so as to be able to be engaged with and detached from the throttle valve, and when the throttle valve is in a low opening range, the throttle valve is engaged with the throttle valve and the throttle valve is closed. an actuator for controlling the opening of the throttle valve, a throttle valve opening detection means for detecting the opening of the throttle valve, and an idle detection means for detecting that the throttle valve is under the control of the actuator;
If the idle detection means detects that the throttle valve is under the control of the actuator, the actuator is driven according to the difference between the actual throttle valve opening and the target idle opening. Equipped with control means,
The load detection means detects the load state of the engine, and when the load detection means detects that the load has decreased from the high load state, the first set opening degree is gradually decreased and held as the calculated opening degree. 1- When the calculated opening degree is much hotter than the second set opening degree which is smaller than the first set opening degree, the decreasing speed of the calculated opening degree is increased;
an opening subtraction means for controlling the decreasing speed of the calculated opening to be small when the calculated opening is smaller than the second set opening;
When the idle detection means detects that the throttle valve is under the control of the actuator and the calculated opening degree is larger than the target idle opening degree, the calculated opening degree is given priority over the target idle opening degree. Degree and "1"
An engine idle speed control device, comprising dashbot control means for sending the calculated opening degree to the control means in order to drive the actuator according to the difference from the recorded opening degree.