JPH0823311B2 - Engine intake air amount control device - Google Patents

Description

The present invention relates to a control device for controlling an intake air amount of an engine, and particularly when shifting from a load operating state in which an engine throttle valve is opened to a fully closed deceleration or idle state. The present invention relates to an engine control device focusing on the adjustment of the intake air amount.

2. Description of the Related Art Conventionally, in an automobile engine, a driver often releases his / her foot from the accelerator pedal and shifts to a deceleration operation while traveling while depressing the accelerator pedal. The transition to deceleration operation causes a large amount of unburned gas to be generated.Therefore, a function commonly called a dashpot for slowly closing the throttle valve and closing the throttle valve to suppress an increase in intake negative pressure during deceleration operation. A function for limiting dynamic operation (that is, a countermeasure function during deceleration operation) is added. The above-mentioned dashpot is typically one that engages with a throttle valve at a low opening position to regulate the moving speed of the valve toward the closed side.

Further, conventionally, in an automobile engine, a target opening of an intake flow control valve represented by a throttle valve or the like is changed to an engine operating state represented by a warm-up state of the engine or an operating state of auxiliary equipment such as an air conditioner. Depending on the setting,
By adjusting the opening of the intake flow control valve to the target opening via an actuator, the intake air amount during idling, that is, the lower limit value of the intake air amount is accurately controlled to obtain an optimum idle speed. Many techniques for so-called aisle rotation speed control have been proposed. In such idle speed control, feedback control of the idle speed is often performed.

As described above, in an automobile engine, it is required to finely adjust the intake air amount,
In order to meet such a demand with an inexpensive and compact device, it is conceivable to perform the above-described deceleration operation countermeasure function and the idle speed control function by a common actuator. Now, focusing on the dashpot function again, in the conventional dashpot, when the throttle valve is opened and the engine shifts to the load operation, the load level during the load operation (that is, the load level during the load operation is (Whatever it is) because the engagement point with the throttle valve was moved by a certain amount in the opening direction, and when the throttle valve returned to the low opening range, it engaged with the throat valve and reduced its closing speed. The following problems have occurred.

Here, the role of the dashpot will be briefly described. First, when the engine is operated at a high load, the intake air amount is large and the supply air-fuel ratio tends to be rich, so the fuel amount added to the intake port also increases vigorously. Further, in this high load state, the output torque of the engine is also large. If the throttle valve is suddenly closed from this state, the intake negative pressure will rapidly increase, the fuel adhering to the port will evaporate and be sucked into the combustion chamber, while the amount of intake air will decrease sharply. It causes a misfire at worst. Also, sudden closing of the throttle causes a sudden decrease in output torque,
It also causes a body shock. Suppressing the sudden closing of the throttle valve by the dashpot function suppresses the occurrence of this over-rich state and the sudden change in output torque, and this dashpot function makes the accelerator pedal abrupt especially during high load operation. It will be understood that it is effective when returned.

By the way, when the throttle is rapidly closed from high load operation, when the driver quickly returns the throttle from the high load state to the throttle fully closed position, and when the driver starts the high load from the middle low load once. There are cases where the pedal return is stopped and then the accelerator pedal is returned until the throttle is fully closed (or the speed is relatively slow even when the throttle is closed rapidly). The former case is the latter case. The degree of overrich is more severe and the degree of torque change is greater than in the case.

On the other hand, when the accelerator pedal is released during medium / low load operation, the occurrence of an overrich state and the output torque change are gentler than in the case of sudden deceleration from high load operation. Focusing on the occurrence, since the amount of fuel adhering to the port during medium load operation is less than the amount of fuel adhering during high load operation, the degree of overrich is lower than during deceleration from high load, which is the case described above. Becomes

Therefore, when decelerating from a medium load or decelerating from a high load, if the time required to fully close the throttle is relatively long, the dashpot function is required as much as when performing a rapid deceleration from high load operation. In addition, excessive dashpot function causes unnecessary air to be supplied to the combustion chamber, resulting in poor fuel economy due to poor engine braking and fuel supply corresponding to unnecessary air. There is a risk.

For this reason, when a certain dashpot function is applied regardless of the load condition as in the conventional device, when the dashpot function is set to respond to the rapid closing of the throttle from a high load, the high load There is a problem that when the engine is returned to the throttle fully closed position from a relatively slow speed, or when the throttle is rapidly closed from medium / low load operation, engine braking and fuel consumption deteriorate.

The present invention is intended to solve such a problem, and further, in order to realize fine adjustment of the intake air amount of the engine with an inexpensive and compact device, a dashpot function and an idle speed control function The object of the present invention is to provide an engine intake air amount control device capable of performing a dashpot function according to the state of deceleration.

Therefore, the engine intake air amount control apparatus of the present invention sets the lower limit value of the intake air amount to the operating state of the engine when the accelerator pedal that is manually operated to set the intake air amount of the engine occupies the idle position. The target opening degree of the intake flow rate control valve provided in the intake passage of the engine is set according to the operating state of the engine, and the opening degree of the intake flow rate control valve is set via the actuator. Which is adjusted to, the idle control amount setting means for setting an idle target opening when the accelerator pedal is in the idle position, a load sensor for detecting the load state of the engine, and the load sensor for detecting. A non-idle system that sets a dashpot initial opening larger than the above idle target opening when the engine load exceeds the set value Amount setting means and a dashpot control amount that gradually reduces the dashpot initial opening to set the dashpot opening when the engine load state switches below the set value after setting the dashpot initial opening. It is characterized by comprising a computing means and a control means for controlling the control valve opening to the dashpot opening through the actuator when the accelerator pedal occupies an idle position and then controlling the opening to the idle target opening. There is.

An intake air amount control device for an engine as an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an overall configuration diagram thereof, FIG. 2 is a block diagram showing a control procedure, FIG. 3 (a), (B), FIG. 4 (a), (b), 5-10
All figures are graphs for explaining its function, No. 11, 1
Figure 2 is a flow chart for explaining the operation, Figure 13
FIG. 3 is a block diagram showing its configuration.

As shown in FIG. 1, in the intake passage 1 of the engine E,
A throttle valve 2 is provided, and this throttle valve 2
The shaft 2a is connected to the throttle lever 3 outside the intake passage 1.

When an accelerator pedal (not shown) is stepped on the end portion 3a of the throttle lever 3, the throttle valve 2 is rotated in the clockwise direction (opening direction) in FIG. 1 via the throttle lever 3. A wire (not shown) is connected, and further, a return spring (not shown) for urging the throttle valve 2 in the closing direction is attached to the throttle valve 2 to reduce the pulling force of the wire. The throttle valve 2 is closing.

By the way, when the engine is idle, the throttle valve 2
An actuator 4 for controlling the opening degree of
The actuator 4 has a DC motor (hereinafter simply referred to as "motor") 5 having a worm 6a on its rotating shaft, and the worm 6a with the motor 5 meshes with an annular worm wheel 6b.

The worm wheel 6b is integrally provided with a pipe shaft 6c having a female threaded portion 6d. It is attached through.

The tip of the rod 7 comes into contact with the end 3a of the throttle lever 3 via the idle switch 9 as an idle sensor when the engine E is in the idle operation state.

Here, the idle switch 9 is a switch that is turned on (closed) in the engine idle operation state and turned off (open) in other states.

A long hole 7b is formed in the rod 7, and a pin (not shown) on the actuator body side is guided in the long hole 7b, which prevents the rod 7 from rotating. I'm sick.

Thus, 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 operation state, by rotating the motor 5 in a predetermined direction, the rod shaft is passed through the worm gear. Rotate 6c,
When the rod 7 is projected (moved forward) from the actuator 4, the throttle valve 2 is controlled to open, and
When the motor 5 is rotated in the reverse direction to retract (retract) the rod 7 into the actuator 4, the throttle valve 2 is controlled to close by the action of the return spring.

A throttle opening sensor 8 for detecting the opening of the throttle valve 2 (throttle opening) is provided. As the throttle opening sensor 8, a potentiometer or the like that generates a voltage proportional to the throttle opening is used. To be

Further, 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 an engine rotation speed by an ignition pulse is provided.

Furthermore, a cooler switch 20 for detecting the on / off state of the cooler is provided, and as the cooler switch 20, for example, a relay is used.

Further, a pressure sensor 21 that detects an intake manifold pressure (here, an absolute value) that is a load of the engine is provided, and outputs a signal according to the absolute value of the intake manifold pressure.

Then, the detection signals from the respective sensors 8, 9, 11, 12, 20, 21 are received, and control signals based on these signals are sent to the actuator 4
There is provided a control unit (computer) 15 which also serves as a control means for outputting to the motor 5, a degree-of-opening subtraction means and a dashpot control means. This control unit 15 detects the idle operation state by the idle switch 9 (idle Under the set condition I (when the switch 9 is turned on) (described later), feedback control of the engine speed (idle speed control) is performed by a signal from the rotation speed sensor 12 while other conditions when the idle state is detected are detected. Under the set condition II (described later), the position feedback control of the throttle valve 2 is performed by the signal from the throttle opening sensor 8.

Here, the condition I means that at least the following items are satisfied, and the condition that the engine is relatively stable.

(1) A predetermined time has elapsed after the idle switch 9 changed 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 speed (actual speed) NR from the target speed NTW must be within a predetermined range.

(4) In a vehicle or the like having a cooler, a predetermined time has elapsed after the cooler relay or the like was switched according to the cooler load.

The condition II means a condition when the condition I is not satisfied, the engine is not relatively stable, and quick feedback control is desired.

Even if either of the above conditions I and II is satisfied, the control unit 15 does not output when it is impossible to control the throttle opening below the minimum opening or above the maximum throttle opening.

Further, the position (reference position) of the rod 7 of the actuator 4 corresponding to the reference opening of the throttle valve 2 (this opening is set as a small opening corresponding to the engine speed of about 600 rpm). A motor position switch 10 is provided as a position sensor for detecting the. That is, this motor position switch 10
Is provided on the rear side of the rear end surface of the rod 7, and is configured to be turned on (closed) in the vicinity of the most retracted state of the rod 7 and turned off (open) at other positions. It is designed to be input to the control unit 15.

Further, as shown in FIG. 2, the control unit 15 receives inputs from the respective sensors 8 to 12, 20, 21 and receives a cold idle mode in a cold engine state, a warm idle mode in a warm engine state, Whether to determine the cooler idle up mode or dashpot mode when using the cooler, and whether to perform feedback control of engine speed (idle speed control), position feedback control of the throttle valve 2, or expected control The control method is determined, the driving time of the motor 5 (including the determination of the rotation direction) is calculated according to the determination result, and the control signal corresponding to this time is output to the motor 5
Can be output to.

Here, the expected control means the following control. That is, in a predetermined operating condition of the engine, for example, when the throttle valve 2 is suddenly closed, in order to gradually decrease the throttle valve opening, the rod 7 is set at a predetermined position (throttle opening corresponding to this position). The degree is referred to as the dashpot opening.) This means that the throttle valve 2 is gradually opened to the desired opening from the dashpot opening with the rapid closing of the throttle valve. It can be reduced to a certain degree.
The mode for performing such control is the dashpot mode.

Hereinafter, the control by the control unit 15 will be described.

First, as a general rule, the processing flow for performing the control is executed in synchronization with the ignition pulse. Note that this main flow is executed in synchronization with a pseudo pulse signal such as a clock having a predetermined cycle when there is no ignition pulse such as when the engine is not operating (when the engine is stalled).

The above-described processing flow may be executed in synchronization with a timer interrupt signal (50 ms timer interrupt signal) having a cycle (for example, 50 ms) in another main flow.

Now, FIGS. 11 and 12 show a processing flow of opening control of the throttle valve 2 including dashpot control.
Terminal B'in the figure is connected to terminal B'in Figure 12,
The "return" in Fig. 12 is connected to the "return" in Fig. 11.

At the time of inserting the ignition key (including the engine start state), the processing flow A, B in the computer 15
Is being started.

Processing flow A is for setting the target opening PS as shown in FIG. 11, and processing flow B is for driving the motor 5 based on the target opening PS etc. as shown in FIG. To do.

First, initialization is performed in A-0, and each flag is
K, S1, S2 ... S5 contents are reset.

Next, at A-1, the target opening PT when the cooler is off
W, target speed NTW when cooler is off, actual opening PR, actual speed NR,
The absolute value PP of the manifold pressure, the cooling water temperature T, etc. are read.

Here, the target opening degree PTW when the cooler is off and the target rotation speed NTW when the cooler is off are discrete values obtained by increasing the cooling water temperature T as shown in FIGS. 3 (a) and 3 (b). In the middle of the processing flow, the numerical value is appropriately determined by the interpolation method.

Hereinafter, the flow of the processing flows A and B with the increase of the cooling water temperature T of the engine will be shown.

i) In the engine cooling state (PTW <Pmax) [Refer to reference numeral G1 in FIG. 3 (a)] This mode is the cold idle mode.
At -2, it is determined based on the information from the cooler switch 20 whether the cooler switch 20 is on.

When the cooler switch 20 is off, A-3
, The target opening PTW when the cooler is off is selected target opening P
It is set to 1, and in A-8, the target opening degree NTW when the cooler is off is set to the target rotation speed NS.

The flow of this processing, A-2, A-3, A-8, is hereinafter referred to as "processing flow Fc1".

Further, when the cooler switch 20 is on, it is determined in A-4 whether or not immediately after the cooler is turned on. If it is immediately after the cooler is turned on, the content of the flag K becomes "1" (A-5), The contents of the flag K are "0" except immediately after turning on. (A-6) Next, in A-7, the target opening PC when the cooler is on
Is below the target opening PTW when the cooler is off (PC≤PTW), the flag K is reset at A-28, and A-
After going through 3, A-8, it reaches A-9.

The flow of this process, A-2, A-4 to A-7, A-28, A-3, A
-8 is hereinafter referred to as "processing flow Fc2".

Next, in A-9, when the set target opening P1 is larger than the dashpot target opening Pmax (P1> Pmax), the YES route is reached to A-26, and this selected target opening P1 is the target. It is set as the opening PS, and the processing flow B from the terminal B '.
Leading to. (The processing flow of A-9 and A-26 is hereinafter referred to as "processing flow Fa1".) In processing flow B, as shown in FIG. 12, it is determined in B-1 whether or not the idle switch 9 is on. If it is on, the YES route is taken and the processing flow F1, Fb described later is executed.
The motor 5 is driven and controlled by 2 and the target opening degree PS (= PTW) and the target speed NS (= N) of the throttle valve 2 in the cold state.
TW).

If the idle switch 9 is off, the NO route is taken, and at each block B-14, B-15, B-23, which will be described in detail later, it is determined as NO at B-24, and no control is performed. To return.

After that, in B-1, it is judged whether or not the idle switch 9 is ON, and if it is ON, B-2, B-
After the flag processing of S4 = 0 and S5 = 0 is performed in 3, the actual opening PR of the register (or RAM address) PM is input in B-4.

Then, in B-5, it is judged from the conditions I and II whether or not the idle speed control (ISC) is OK (possible), and if it is possible (YES), B- In 6, ΔN
= NS-NR is calculated, and if it is not possible, ΔP = PS-PR is calculated at B-11 to perform position feedback control.

Here, the target rotation speed NTW is stored in NS as described above, and the target opening degree obtained in the processing flow A is stored in PS.

After the calculation of B-6 and B-11, B-7 and B-1
In 2, the driving time ΔD of the motor 5 is calculated from ΔN or ΔP, respectively.

Here, examples of the ΔP-ΔD characteristic and the ΔN-ΔD characteristic are as shown in FIGS. 4 (a) and 4 (b).

Furthermore, after the treatment of B-7 and B-12, B-8 and B-1
At 3, it is determined whether each ΔD can be set.

In the case of position feedback control (B-
13) is determined to be possible (YES) when 100 ms has elapsed, and is not possible (NO) otherwise, and in the case of engine speed feedback control (B-8), it is longer than in the above case. For example, it is determined that it is possible if 700 ms has elapsed, otherwise it is determined to be impossible.

That is, 100ms for position feedback control
It is possible to control every interval, and with engine speed feedback control, it is possible to control every 700 ms intervals.

Thereafter, in B-9, ΔD is set in the motor driving timer, and in B-10, the motor is driven until the timer becomes zero.

As a result, in both cases of engine speed feedback control and position feedback control,
The engine is instantly controlled in a target state according to the cooling water temperature and the like. That is, the engine idle speed can be controlled to an optimum state.

If NO in either B-8 or B-13, the motor drive control is not performed and the process is returned.

The above-mentioned processing flow B-1 to B-10 is hereinafter referred to as "immediate processing flow Fb1", and the processing flow B-1 to B-5, B-
11 to B-13, B-9, B-10 are referred to as "immediate processing flow Fb2"
Call.

By the way, when the idle switch 9 is off, B-
Take NO route at No. 1, and at B-14, S5 = 1
Whether or not it is determined.

Since S5 = 0 here, the NO route is taken, and at B-15, it is judged by the flag S1 whether or not immediately after the manifold pressure becomes large.

When it is not immediately after the manifold pressure becomes large, it is judged whether or not S4 = 1 and K = 1 at B-23 and B-24 respectively through the NO route, and since both are NO, it is returned. . (Hereinafter referred to as "processing flow Fd1.") By the way, in this engine cold state, the cooler is on (K =
In the case of 1), the flow of processing is almost the same as when the cooler is turned on in the engine warm-up state, and the details thereof will be described later.

ii) In the engine warm-up incomplete state (Pmax ≧ PTW ≧ PC) [Refer to reference numeral G2 in FIG. 3 (a)] When the cooler switch 20 is off, the processing flow is the processing flow Fc1 in the engine cold state described above. The flow of processing is the same as that of, and then at A-9, P1 (= PT
From W) ≤ Pmax, it is determined to be NO and A-10 is reached.

In A-10, it is judged whether or not the manifold pressure PP (absolute value) from the manifold pressure sensor 21 has continued for a predetermined value or longer and for a predetermined time or longer. For example, whether PP> 660 mmHg and 1 second or longer (this The condition is hereinafter referred to as "manifold pressure condition".) It is determined.

Here, since the manifold pressure PP does not satisfy the manifold holder pressure condition, the NO route is taken, and at A-13, it is determined by the flag S2 whether or not the manifold pressure condition is satisfied in the previous routine. Here, S2 = 0 Because there is NO
Take the route to A-14.

At A-14, it is judged whether or not the flag S3 is set. Since S3 = 0 here, the NO route is reached to A-26. Then, the above-mentioned process PS = P1 is performed at A-26, and the process goes from A-26 to the terminal B '.

Here, the processing flow, A-10, A-13, A-14, A-26,
Hereinafter, it is referred to as "processing flow Fa2".

In the engine warm-up incomplete state, the flag processing other than the flag K is not performed in the processing flow A, so that the mode in the processing flow B is almost the same as the engine cold state.

iii) In the engine warm-up state (PTW> PC) [Refer to G3 in Fig. 3 (a)] This mode includes the warm-up idle mode, cooler idle mode, cooler idle up mode, and dashpot mode.

The processing flow in the engine warm-up state will be described with reference to FIG.

First, from time t0 to immediately before time t1 (hereinafter; "time t0 ~
t1 ”. It will be omitted according to the other time. )
Since the cooler switch 20 is in the off state and the idle switch 9 is in the on state, the target opening degree PTW when the cooler is off is set to the target opening degree PS through the processing flows Fc1 and Fc2.

Then, in the processing flow B, since the idle is on, the immediate processing flows Fb1 and Fb2 are performed by the YES route. As a result, the throttle opening instantly becomes the idle position shown in FIG.

Next, at time t1, when the cooler switch 20 is turned on (cooler ON), the flag K indicating immediately after the cooler is turned on is set via A-2, A-4, A-5, and at A-7, Since the target opening PTW when the cooler is off is smaller than the target opening PC when the cooler is on, take the YES route and go to A-1
In 1, the target opening PC when the cooler is on is selected target opening P
It is set to 1, and in A-12, the target opening NC when the cooler is on is set to the target rotation speed NS.

The flow of this process, A-2, A-4 to A-7, A-11, A-12
Is hereinafter referred to as "processing flow Fc3".

At time t1, the target opening PS is changed to the selected target opening P1 at A-26 through the processing flow Fc3 and the processing flow Fa2.
(Here, the target opening PC when the cooler is on) is set,
The motor 5 is drive-controlled to the target opening degree PS and the target rotation speed NS by the immediate processing flows Fb1 and Fb2. That is, the throttle opening instantly becomes the cooler position shown in FIG.

From time t1 to t2, the flag K is reset at A-6, but the other processes are the same as those at time t1.

At time t2, the engine is idle off (OFF), so the target opening PS remains set to the target opening PC when the cooler is on.
It arrives at B-1 and takes the NO route from B-1 to B-14.

At B-14, it is judged whether or not the flag S5 is set, and if it is set, it returns via YES route, and if it is reset, it passes through NO route and B-15.
Go to

At B-15, it is determined whether or not the flag S1 indicating immediately after switching to the dashpot mode is set, and since S1 = 0 here, S23 goes through the NO route to B-23.

At B-23, it is judged by the flag S4 whether or not it has passed through the opening degree holding processing flow Fb3 which will be described later. Since it does not pass here, it goes to B-24 via the NO route.

In B-24, it is determined whether or not it is immediately after the cooler is turned on. Here, the motor 5 is not driven through the NO route and returns.

From time t2 to t3, the same processing as the above-described processing at time t2 is performed.

At time t3, as shown in FIG. 5 (a), the manifold pressure satisfies the above-mentioned manifold condition (reference numeral T1 in FIG.
After a predetermined time (here, 1 second) has elapsed (see reference numeral T2 in the figure), the dashpot mode (D / P) is set.

That is, after the processing flows Fc2 to Fc3 have passed, A-10
In, it is determined that the manifold pressure is high, and the route is A-21 via the YES route.

For A-21, if it is immediately after the manifold pressure becomes large, that is, immediately after switching the dashpot mode, YES
Take the route, set the flag S1 at A-24, and take the NO route if it is not immediately after switching, then go to A-22
At S1, the flag S1 is reset, and in either case, A-23 is reached next.

Here, it reaches A-23 from A-21 through A-24.

A-23 is a flag that indicates that the dashpot mode is in progress.
S2 is set, then, at A-25, the dashpot initial opening Pmax is set to the target opening PS, and the terminal B'is reached.

The flow of this processing, A-10, A-21 to A-25, is hereinafter referred to as "processing flow Fa3".

After this process flow Fa3, idle off and S5 =
Since it is 0, the NO route is taken in B-1 and B-14 to reach B-15.

In B-15, immediately after switching to the dashpot mode (S1
= 1), take the YE route and reach B-16.

At B-16, the flag S5 indicating the processing immediately after the idle off (for example, when the accelerator pedal is depressed) and the dashpot mode switching is set, and at B-17, the flag S4 is determined, and S4 = 0 in this case. , B-19.

At B-19, ΔP = PS-PM is executed to obtain the difference between the target opening PS and the selected target opening P1, and at B-19, according to this (target opening-selected target opening) ΔP. .DELTA.D is set, and .DELTA.D is set in the motor driving timer at B-21, and the motor is driven at B-22 until the timer becomes zero.

The flow of this process, B-14 to B-17, B-20, B-19, B-2
Hereinafter, 1 and B-22 are referred to as "processing flow Fb3".

As a result, in the case of the dashpot mode switching control, the throttle valve 2 is instantly controlled by the dashpot opening. That is, the engine idle speed can be controlled to an optimum state.

Then, from time t3 to t4, first, the NO route is taken from A-21, the flag S1 is reset, and the processing flow Fa3
In process flow B, the process at time t3 (S5 = 1) causes a return from B-14 via the YES route (hereinafter referred to as “process flow Fd2”).

Other processes in the times t3 to t4 are the same as those in the time t3.

Then, at the time t4 and the times t4 to t5, the cooler is turned off (cooler OFF), so that P1 = PTW and NS = NTW are set.

Next, when the manifold pressure decreases, as indicated by reference numeral T3 in FIG. 5 (a), when the idle switch 9 is turned on almost at the same time, the throttle valve 2 is operated by the dashpot, and the opening degree gradually increases. Is controlled to be small.

That is, at time t5 (= t6), the processing flow goes from the A-10 through the NO route of the processing flows Fc1, A-9 to the A-13 through the NO route.

At A-13, it is determined whether or not the dashpot mode is disclosed by the flag S2. Since S2 = 1 here, the YES route causes the flag S2 to be reset at A-18 to A-20, Set the flag S3 that indicates the start of the countdown of the dashpot target opening (position) within 15
The dashpot target opening degree PO within 15 is once set to the dashpot initial opening degree Pmax.

Then, at A-27, the dashpot target opening degree PO in the computer 15 is set to the target opening degree PS, and the terminal B'is reached.

The flow of this process, A-10, A-13, A-18 to A-20, A-27
Will be hereinafter referred to as processing flow Fa4].

Next, since the idle is on, the flow immediately goes from B-1 through the YES route to the immediate processing flow Fb1 or Fb2.

Here, t5 = t6, so in the immediate processing flow,
The throttle valve 2 is controlled to maintain the dashpot opening.

Then, from time t5 to t7, NO of the processing flow Fc1, A-9
Route A, NO route of A-10, A-13, it is determined by the flag S2 whether or not the down-count of the target opening in the computer 15 has started in the dashpot mode (S2 = 0). Since it has started, take the NO route to reach A-14.

At A-14, the flag S3 indicating that the dashpot calculation opening degree PO is gradually decreasing (down) is determined. Here, since it is down, the YES route is taken,
The calculation of PO = PO-ΔP ₀ is performed using the step opening ΔP ₀ which is the predetermined reduction amount of the throttle opening.

Then, in A-16, it is determined whether or not PO> P1. Here, since P1 = PTW is set by the cooler off, PO> P1 is satisfied, the YES route is taken, and A
At -27, the dashpot calculated opening PO, which has become smaller by one step, is set as the target opening PS.

The flow of this processing, A-10, A-13 to A-16, A-27, is hereinafter referred to as "processing flow Fa5".

Next, since the idle is on, the flow immediately goes from B-1 through the YES route to the immediate processing flow Fb1 or Fb2.

At time t7 and time t7 to t8, the cooler is turned on, and therefore P1 = P at A-11 and A-12 according to the processing flow Fc3.
C and NS = NC, and the same processing flow Fa5 as at times t6 to t7 is passed, but the determination condition at A-16 is at times t6 to t.
Although it differs from 7, the judgment result is also YES.

Since the idle is on, the flow immediately goes from B-1 to the immediate processing flow Fb1 or Fb2 via the YES route.

At time t8, the process reaches A-16 similarly to the processing flow at time t7 and times t7 to t8, and NO is determined at A-16.

Then, in A-29, it is determined that PO> PTW,
In this case, take the YES route to A-26.

In A-26, the target opening degree PS is set to the selected target opening degree P1 (here, the target opening degree PC when the cooler is turned on by the processing at the time t7 and the times t7 to t8).
Proceed from 26 to terminal B '.

Flow of this processing, A-10, A-13 to A-16, A-29, A-26
Is hereinafter referred to as "processing flow Fa6". In addition, also in this processing flow Fa6, the subtraction is executed every time at A-15, and the dashpot opening degree PO is decreased by ΔP ₀ .

Next, since the idle is on, the flow immediately goes from B-1 through the YES route to the immediate processing flow Fb1 or Fb2.

From time t8 to t9, the same process flow Fc3, Fa6, as at time t8,
By (Fb1 or Fb2), the throttle opening is maintained at the target opening PC when the cooler is on.

At time t9, the cooler is turned off, so that P1 = PTW and NS = NTW are set by the processing flow Fc1.

Then, through the NO route from A-9, the dashpot calculation opening degree PO in the computer 15 is set to the target opening degree PS at A-16.

Dashpot calculation opening PO is processing flow Fa5 and F
Since ΔP _{0 is} subtracted by a6 at a6, as shown by the broken line in FIG. 6, the value continues to decrease at a predetermined gradient and the value at time t9 is set as the target opening PS.

From time t9 to t10, similarly to the processing at time t9, the NO route of the process flow Fc1, A-9 and the process flow Fa5 are executed, and the throttle opening gradually decreases to the opening at the time of idling.

Next, since the idle is on, the flow immediately goes from B-1 through the YES route to the immediate processing flow Fb1 or Fb2.

If you do not activate the cooler at time t7,
From time t6 to time t10, as shown in FIG. 10, the throttle opening gradually decreases in the dashpot state, and the dashpot control function is fully exerted in the state in which the accelerator pedal is not depressed.

At time t10, the NO route of the process flow Fc1, A-9 is executed as in the process of the time t9 to t10, and the process up to A-16 is performed similarly to the process flow Fa5.
At -16, it is determined that PO> P1 is not established, and after passing through the NO route, at A-29, it is determined that PO> PTW is not established, the NO route is taken, and the routine proceeds to A-17.

At A-17, the flag S3 is reset to display the end of the dashpot calculation in the computer 15.

In A-26, the selected target opening P1 (= PTW) is changed to the target opening PS
To reach terminal B '.

The flow of this processing, A-10, A-13 to A-17, A-26, is hereinafter referred to as "processing flow Fa7".

Next, since the idle is on, the flow immediately goes from B-1 through the YES route to the immediate processing flow Fb1 or Fb2.

After time t10, the processing flow Fc1 and A-9
Then, the processing flow Fa2 is executed by S3 = 0 through the NO route.

Next, since the idle is on, the flow immediately goes from B-1 through the YES route to the immediate processing flow Fb1 or Fb2.

Next, another process in the engine warm-up state will be described with reference to FIG.

First, at the time t0, the NO route of the process flows Fc1, A-9, the process flow Fa2, and the process flows (Fb1 and Fb2) are executed as at the time t0.

Then, at time t11, when the idle is turned off,
After the processing flow Fa2 is executed through the NO route of the processing flows Fc1 and A-9 as at the time t0, N is set in B-1.
Take the O route.

Then, the processing flow Fd1 is taken, and the process ends without driving the motor 5.

Next, at time t12, the same processing as at time t11 is performed, and after reaching B-24, it is immediately after the cooler is turned on.
It is judged that K = 1 at -24, and through the YES route, B-25
Then, the cooler on history after idle off is set, that is, the flag S4 is set.

Then, at B-20, a difference ΔP (= PS-PM) between the actual opening PR when the idle switch 9 is turned on (here, the actual opening PR immediately before time t11) and the target opening PS is calculated. To be done.

Then, at B-19, this (target opening-time t11
(Actual opening immediately before) ΔD is set according to ΔP, and
At -21, set ΔD to the motor driving timer,
At B-20, the motor is driven until the timer reaches 0.

The flow of this process, B-14, B-15, B-23 to B-25, B-2
Hereinafter, 0, B-19, B-21, B-22 are referred to as "processing flow Fb4".

Then, at time t13, when the manifold pressure next satisfies the above-mentioned manifold condition, S1 becomes 1, and the processing flow A and B-1, B-14 at time t12 is executed, and then B At -15, take the YES route and go to B
After -16, in B-17, the cooler on history after idle off is determined. Since there is history here, YES
Take the route to B-18.

In B-18, ΔP = PS−P1 is executed, where the selected target opening P1 is set to the target opening PC when the cooler is on, and the target opening PS is the dashpot initial opening Pmax.
Therefore, the drive control of the motor 5 to the dashpot initial opening Pmax is performed at B-18, B-19, B-21, B-22.

The flow of this processing, B-14 to B-19, B-21, B-22, is hereinafter referred to as "processing flow Fb5".

In this way, each processing flow A, B is performed.

By the way, to explain the case where the time t5 and the time t6 in FIG. 6 do not match, as shown in FIG.
At time t14 (time when the manifold pressure is switched corresponding to time t5 in FIG. 6), the dashpot calculation opening degree PO in the computer 15 starts subtraction [see FIG. 5 (c)], but at time t15. Up to [see T5 in FIG. 5 (b)], the dashpot initial opening Pmax is maintained, and the dashpot function is first exhibited when the idle switch 9 is turned on at time t15. The dashpot operates until t16. [Refer to FIG. 5 (b)] As shown in FIG. 5 (c), the calculation (subtraction) start time TP may be set appropriately.

Further, reference numeral T3 in FIGS. 5A to 5C indicates a time when the manifold pressure becomes equal to or lower than a predetermined pressure, T4 is a calculation start time of the calculation opening, and T5 is an idle switch 9 ON state. , T6 indicates the end time of the subtraction.

It should be noted that at time t17 in FIG. 8, an example in which the engine is idled off at times t6 to t7 in FIG. 6 is shown.
The process flow B is reached through the NO route of Fc1 and A-9 and the process flow Fa5.

Next, since the idle state is off, the current idle opening degree is maintained by the process flow Fd1 via the NO route from B-1.

 This process is executed until immediately before time t8.

Also, at time t19, the target opening PC when the cooler is on
To the fast (high speed) idle opening degree shown at time t20 and after in FIG. 9 are also appropriately executed.

Further, the present apparatus can be applied to an engine having a carburetor type fuel supply system and an engine having an injector type fuel supply system.

As described above, in this embodiment, when the accelerator pedal (acceleration control member) is in the idle position, the idle control amount setting means sets the idle control amount of the actuator corresponding to the idle target opening PTW.PC. It
That is, in the idle control amount setting means, the processing flow Fc
The idle target opening degree PS is set as PS = PTW or PS = PC by 1, Fc2, Fc3, Fa1, Fa2 (see FIG. 11).

When the engine load becomes higher than the set value,
The dashpot initial control amount is set by the non-idle control amount setting means, the dashpot initial opening Pmax is set by this, and then the dashpot initial opening is gradually reduced when the load decreases. The calculated control amount, that is, the dashpot calculated opening degree PO is set by the control amount calculation means, and when the accelerator pedal returns to the idle position, the actuator is controlled based on the dashpot calculated control amount, whereby the throttle valve ( The opening degree of the intake air flow rate control valve 2 is adjusted to be gradually reduced. At that time, when the accelerator pedal rapidly moves from the high load position to the idle position, the dashpot calculation control amount immediately after the accelerator pedal returns to the idle position is relatively large, so the dashpot function is exerted strongly. On the other hand, when the accelerator pedal moves from the high load position to the idle position relatively slowly, the dashpot calculation control amount immediately after the accelerator pedal returns to the idle position decreases, so the dashpot function becomes weaker. To be demonstrated.

A block diagram of the configuration of the engine intake air amount control device of the present invention is as shown in FIG. 13. According to this control device, when the engine load becomes a high load state equal to or higher than a set value, non-idle operation is performed. The dashpot initial opening degree is set by the control amount setting means, and when the load is reduced thereafter, the dashpot opening degree obtained by gradually reducing the dashpot initial opening degree is set by the dashpot control amount calculating means. When is returned to the idle position, control is performed to set the idle intake flow control valve opening of the engine to the above-mentioned dashpot opening through the actuator and then to the idle target opening. Therefore, when the accelerator pedal rapidly shifts from the high load position to the idle position, the dashpot opening immediately after the accelerator pedal returns to the idle position is relatively large, so the dashpot function is exerted, while the accelerator pedal is activated. When the vehicle shifts from the high load position to the idle position relatively slowly, the dashpot opening is reduced immediately after the accelerator pedal returns to the idle position, so the dashpot function is exerted weakly. In this way, a dashpot device is realized inexpensively and compactly by using an actuator capable of exerting an idle speed control function, which causes the dash port to act when the engine load is reduced, resulting in an over-rich state and output torque change. It is possible to prevent the occurrence of defects based on Also, at that time, the dashpot mechanism is appropriately exerted according to the load state and the load reduction state immediately before the load reduction state occurs, so that it is possible to prevent the dashpot from acting more than necessary and to prevent the engine braking. There are advantages such as better fuel consumption and better fuel economy.

[Brief description of drawings]

FIG. 1 shows an engine intake air amount control apparatus as one embodiment of the present invention. FIG. 1 is an overall configuration diagram thereof, FIG. 2 is a block diagram showing the control procedure thereof, FIG. 3 (a),
(B), FIGS. 4 (a) and (b), and FIGS. 5 to 10 are all graphs for explaining the action, and FIGS. 11 and 12 are flow charts and diagrams for explaining the action. FIG. 13 is a block diagram showing its configuration. 1 ... Engine intake passage, 2 ... Throttle valve, 2a ...
Shaft, 3 ... Throttle lever, 3a ... Throttle lever end, 4 ... Actuator, 5 ... Motor, 6a ... Worm, 6b ... Worm wheel, 6c ... Pipe shaft, 6d
...... Female thread, 7 …… Rod, 7a …… Male thread, 7b ……
Slotted hole, 8 ... Throttle opening sensor, 9 ... Idle switch (idle sensor), 10 ... Motor position switch (position sensor), 11 ... Water temperature sensor, 12 ...
... Rotation speed sensor, 15 ... Control unit (computer) that also serves as control means, opening subtraction means and dashpot control means, 20 ... cooler switch, 21 ... manifold pressure sensor as load sensor, E ... engine.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-57-124037 (JP, A) JP-A-51-106475 (JP, A) JP-A-53-148625 (JP, A)

Claims (1)

[Claims] 1. An intake passage of an engine for setting a lower limit value of the intake air amount according to an operating state of the engine when an accelerator pedal operated to set an intake air amount of the engine occupies an idle position. A target opening degree of an intake flow rate control valve provided in the engine is set according to an operating state of an engine, and the opening degree of the intake flow rate control valve is adjusted to the target opening degree via an actuator. When the engine is in the idle position, an idle control amount setting means for setting an idle target opening, a load sensor for detecting the load state of the engine, and a high load in which the load of the engine detected by the load sensor is a set value or more. Is set to a non-idle control amount setting means for setting a dashpot initial opening larger than the above idle target opening, and a dashpot initial opening. After setting, when the load condition of the engine switches below the set value, the dashpot control amount calculation means for gradually reducing the dashpot initial opening to set the dashpot opening, and the accelerator pedal are set to the idle position. An intake air amount control apparatus for an engine, comprising control means for controlling the opening of the control valve to the opening of the dashpot via the actuator when the valve is occupied and then controlling the opening to the idle target opening.