JPH06100121B2 - Engine intake air amount control device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine intake air amount control device for controlling an engine speed (engine speed) and the like when an engine is in an idle operation state.

(Prior Art) Conventionally, in this type of device, the engine speed and feedback control of the engine speed are detected under relatively stable conditions during idle operation by detecting the engine speed, the opening of the throttle valve, and the like. While performing (idle speed control),
It has been proposed that the position feedback control of the throttle valve can be performed under conditions where relatively quick control is desired during idle operation.

However, such a conventional device has a problem that a large amount of unburned gas is generated when the throttle opening is rapidly reduced in a state where the throttle valve opening is reduced.

On the other hand, when the idle switch is closed (ON), 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 to control the throttle valve. It is conceivable that the valve is gradually returned to the minimum opening state.

(Problems to be solved by the invention) In such a case, when the idle switch is off,
Even in the deceleration state after the engine is in the medium load state, the dashpot is operated.

However, when decelerating from a medium load state, unlike the deceleration state after becoming a high load state, a dashpot is not necessary, and by applying a dashpot,
It has the drawback that the engine brake will not be applied well, and fuel consumption will be poor.

Further, when the throttle valve is rapidly closed and decelerated, the engine output (torque) changes greatly, so that a shock is transmitted to the vehicle body, and this shock is particularly remarkable in a vehicle having an FF lateral engine.

That is, if the time variation of the engine output is large,
The shock will be great. Therefore, by performing the dashpot control, it is possible to reduce the temporal change width of the engine output, but in the conventional proposals, it is necessary to set a uniform touch opening.

That is, since the touch opening degree during deceleration from the low load area and the touch opening degree during deceleration from the high load area are the same, the opening degree is set high even after the return stall.

In the case of this conventional case, on the contrary, when decelerating from the low load range, the engine output rises.

(Means for Solving Problems) The present invention relates to a throttle valve 101 provided in an intake passage of an engine, and a valve that is detachably provided to the throttle valve 101.
An actuator 102 that controls the opening of the valve 101 by variably setting the fully closed position of the valve 101, and the throttle valve 101 described above.
When the idle detection means 104 detects whether the throttle valve 101 is at the fully closed position and the idle detection means 104 detects that the throttle valve 101 is at the fully closed position. First control means 105 for supplying a control signal to the actuator 102 so that the engine speed becomes a desired idle speed, and target position setting means 107 for setting an actuator target position according to the operating state of the engine. A holding means 103 for holding actual position information regarding the actuator 102 both when the throttle valve 101 is in the fully closed position and when the throttle valve 101 is separated from the fully closed position; and when the setting condition is not satisfied. The target position setting means 107 sets both when the throttle valve 101 is at the fully closed position and when it is released from the fully closed position. That the target position and the holding means 103 and the second supplies a control signal to the actuator 102 as by comparing the actual position information the position of the actuator 102 becomes the target position to hold the
Control means 108 and load detecting means 106 for detecting the load state of the engine, and the target position setting means 107
Is to increase the full-closed position as the engine load increases in the off-idle load state corresponding to the state where the throttle valve 101 is separated from the full-closed position based on the detection result of the load detection means 106. When the target position is set and the load condition of the engine is lower than the load condition corresponding to the target position, or when the load condition of the engine becomes the low load condition, the throttle valve 101 is gradually closed. The target position is set so as to be displaced.

(Operation) The actuator 102 controls the opening degree of the throttle valve 101 by variably setting the fully closed position of the throttle valve 101, and the idle detection means 104 detects whether or not the throttle valve 101 is at the fully closed position. . The first control means 105 is the throttle valve 101.
Is in the fully closed position, the idle detection means 104
Is detected and the control signal is supplied to the actuator 102 so that the engine speed becomes the desired idle speed when other set conditions are satisfied, and the holding means 103 has the throttle valve 101 in the fully closed position. The actual position information regarding the actuator 102 is held at both the time and the time when the actuator is separated from the fully closed position. The second control means 108 retains the target position set by the target position setting means 107 when the throttle valve 101 is in the fully closed position and when the throttle valve 101 is separated from the fully closed position when the setting condition is not satisfied. The actual position information held by the means 103 is compared and a control signal is supplied to the actuator 102 so that the position of the actuator 102 becomes the target position, and the load detecting means 106 detects the load state of the engine. The target position setting means 107 sets an actuator target position according to the operating state of the engine, and based on the detection result of the load detecting means 106, the off-idle load state corresponding to the detached state of the throttle valve 101 from the fully closed position. Sometimes, the target position is set to make the fully closed position larger as the engine load increases, and when the load condition of the engine is lower than the load condition corresponding to the target position, or when the load condition of the engine is the low load condition. When released, the target position is set so that the throttle valve 101 is gradually displaced toward the closing side.

(Example) Next, an example of the present invention will be described.

As shown in FIG. 2, a throttle valve 2 is arranged in the intake passage 1 of the engine E, and a shaft 2 a of the throttle valve 2 is connected to a 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. 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, an actuator 4 for controlling the opening of the throttle valve 2 at the time of engine idle operation is provided, and this actuator 4 is provided with a DC motor (hereinafter simply referred to as "motor") 5 having a worm 6a on its rotating shaft. 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 screw portion 6d. The rod 7 having a male screw portion 7a screwed to the female screw portion 6d of the pipe shaft 6c is provided with the worm wheel 6b and the pipe shaft 6c. 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 detecting means 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.

The rod 7 is formed with an elongated hole 7b.
A pin (not shown) on the actuator body side is guided to 7b, whereby the rotation of the rod 7 is prevented.

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. When 6c is rotated and 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 reverse spring.

A motor position sensor 8 for detecting the position of the rod 7 is also provided.
As such, a potentiometer or the like that generates a voltage according to the position of the rod 7 is used.

Further, a water temperature sensor 11 for detecting a cooling water temperature as a warm-up temperature of the engine E is provided, an engine speed sensor 12 for detecting an engine speed by an ignition pulse, and a pulse having a frequency proportional to the vehicle speed is detected. A vehicle speed sensor 22 is provided which produces a signal.

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 throttle sensor 21 for detecting the throttle opening indicating the load state of the engine is provided, and as the sensor 21, a potentiometer or the like for generating a voltage proportional to the throttle opening is used.

Then, the control unit 15 forming first to third control means for receiving the detection signals from the sensors 8, 9, 11, 12, 20, 21 and outputting the control signals based on these signals to the motor 5 of the actuator 4. The control unit 15 is provided with a signal from the rotation speed sensor 12 under the set condition I (described later) when the idle operation state is detected by the idle switch 9 (when the idle switch 9 is on). While the engine speed feedback control (idle speed control) is performed by the above, the position feedback control of the rod 7 is performed by the signal from the motor position sensor 8 in the operating state under the condition I including the off-idle time. When the idle switch 9 is on and the condition I is not satisfied, the throttle valve 2 is under the control of the rod 7, so that the position feedback control of the throttle valve 2 is performed.

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) A predetermined time has passed since the end of the dashpot control.

(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.

Further, when the idle switch 9 is on and the above condition I is not satisfied, the engine is relatively unstable,
This is a case where quick feedback control is desired.

The control unit 15 constitutes a first control means 105, a target position setting means 107, and a second control means 108, and an intake air flow control valve 101 is a throttle valve 2 interlocked with an accelerator pedal, and a bypass intake air bypassing the throttle valve 2. It is composed of a bypass valve provided in the passage. Although the DC motor 5 is used as the actuator 4, a stepping motor or a linear solenoid may be used. Holding means 103
When the actuator 4 uses a DC motor or a linear solenoid, it is composed of a sensor 8 that detects actual opening information and an address of a random access memory (RAM) that stores the output result of this sensor 8. When the actuator uses a stepping motor, it is composed of a RAM address that stores actual opening information after calibration. Although the throttle sensor 21 is used as the load detecting means 106, a sensor for detecting the manifold negative pressure or a means for obtaining the intake air amount / engine speed may be used. Throttle sensor (potentiometer) 21 and load detection means 10
When used as 6, since the output voltage of the throttle sensor 21 can be used as it is as the target value of the motor position sensor 8, the storage area in the control unit 15 is used as a data storage place for converting the motor position target value in the loaded state. It is not necessary and can be constructed at low cost.

The control unit 15 performs predictive control. This predictive control means that the rod 7 is preliminarily reduced in order to gradually reduce the throttle valve opening when, for example, the throttle valve 2 is suddenly closed under a predetermined engine operating condition. This is a control for moving forward to a certain position (the throttle valve opening corresponding to this position is called the dashpot initial opening) by anticipation.

The control unit 15 is composed of a computer or the like and operates by a program and fixed data in a read only memory (ROM), and FIG. 7 shows its main routine.

The control unit 15 starts by inserting the ignition key and first initializes in step S1 and then in step S2.
The data (PR, NR, TW, θR ...) From the motor position sensor 8, engine speed sensor 2, water temperature sensor 11, throttle sensor 21, idle switch 9, cooler switch 20, vehicle speed sensor 22, etc. is read. Then step S3
In step S4, the value NS (TW) corresponding to the engine cooling water temperature TW detected by the water temperature sensor 11 is read and set as the idle target speed NS from the ROM, and the basic target position PS of the actuator 4 from the ROM is read from the water temperature sensor 11 in step S4. The value PS (TW) corresponding to the engine cooling water temperature TW detected by is read and set. Here, the idle target speed NS, the relationship between the idle target speed NSC when the cooler is on and the cooling water temperature TW, the basic target position PS, the basic target position PSC when the cooler is on, the target position PSD corresponding to the dashpot initial opening DP, and the cooling Water temperature T
The relationship with W is set as shown in FIGS. 4A and 4B, and the target position corresponding to the dashpot initial opening DP is set.
The PSD is displaced by the throttle valve opening as described later. Next, in step S5, the on / off state is judged by the signal from the cooler switch (CSW) 20, and if the cooler switch 20 is on, the timer is set after the cooler is turned off in step S7, and the idle target speed NS is turned on in step S8. Whether or not it is smaller than the target rotation speed NSC. If the idle target speed NS is smaller than the cooler-on target speed NSC, in step S9 the idle target speed NS is set to the cooler-on target speed NSC and the basic target position PS is set to the cooler-on basic target position PSC. Proceed to S10. If the idle target speed NS is not lower than the cooler-on target speed NSC, the process directly proceeds to step S10.If the cooler switch 20 is off, the timer after the cooler is turned on is set at step S6 and the process proceeds to step S10. Idle target speed NS and basic target position PS are cooling water temperature TW
Will be maintained at the value corresponding to. Thus, in steps S3 to S9, the idle target speed NS and the basic target position NS
Set PS.

Next, at step S10, it is judged from the signal from the idle switch (ISW) 9 whether or not the engine is in the idle operation state. If the idle switch 9 is off, at step S11 the throttle valve opening θ is judged by the signal from the throttle sensor 21.
It is determined whether R is larger than the upper limit value θS1, and if the throttle valve opening θR is larger than the upper limit value θS1, step S1
At 2, the throttle valve opening θR is limited to the upper limit value θS1. Then, in step S13, the throttle valve opening θR is the lower limit value θR2.
If the throttle valve opening θR is smaller than the lower limit value θR2, the throttle valve opening θR is limited to the lower limit value θR2 in step S14. Then step S1
At 5 the dashpot initial opening DP is set to the throttle valve opening θR
Is calculated in accordance with, for example, DP = K × θR (K is a constant). Therefore, as shown in FIG. 6, the dashpot initial opening DP is the throttle valve opening θR at step S11.
The upper limit value DP by being limited to θS1 to θS2 in S14
Limiting from _max to the lower limit value DP _min , it is obtained in step S15 in proportion to the throttle valve opening θR.

Next, in steps S16 to S18, the dashpot initial opening DP is set in the memory area, but the dashpot initial opening DP obtained in step S15 is the previous value in the memory area.
Only when it is larger than MDP, this value MDP is updated to the value DP obtained this time. That is, in step S16, the determination of MDP <DP is made. Only when MDP <DP, MDP is updated to DP in step S17, the dashpot calculation start flag L is set in step S18, and the counter K is reset in step S19. Proceed to step S22.

When the idle switch 9 is on, the dashpot flag L is checked in step S20, and when the flag L is set, the dashpot initial opening MDP is subtracted by the predetermined opening DP × K in step S21, and the process proceeds to step S22. By repeating this subtraction, the initial opening MDP of the dashpot decreases stepwise. If the flag L has been reset, the process proceeds to step S19, the counter K is reset, and the process proceeds to step S22.

In step S22, the dashpot initial opening MDP is compared with the basic target position PS, and if MDP> PS, the basic target position PS is set to the dashpot initial opening MDP in step S23 in order to perform expected control, In S24, set the timer after the dashpot and proceed to step S27. If not MDP> PS, the dashpot initial opening MDP is reset to 0 in step S25, the dashpot flag L is reset in step S26, and the process proceeds to step S27.

Next, in step S27, the signal from the idle switch (ISW) 9 is used to judge the on / off state, and if the idle switch 9 is off, the timer immediately after the idle switch is turned on is set in step S28, and the engine speed feedback (NFB ) Reset the flag and step S2
Return to.

When the idle switch 9 is on, steps S30 to S
At 36 and S29, the condition I is judged and the NFB flag is set or reset, and the process returns to step S2. That is, in step S30, it is determined whether or not the timer immediately after the idle switch is turned on is 0, and if it is 0, the process proceeds to step S31 and it is determined whether or not the continuous speed pulse timer is 0. Vehicle speed pulse timer is 0
In the case of, the process proceeds to step S32 to determine the on / off state by the signal from the cooler switch (CSW) 20, and if the cooler switch 20 is on, the process proceeds to step S33 to determine whether the timer after cooler on is 0 or not. To do. Again step
If the cooler switch 20 is off in S32, the process proceeds to step S34, and it is determined whether or not the timer after cooler off is 0, and if the timer after cooler off is 0 or if the timer after cooler on is 0 in step S33, go to step S35. Then, it is determined whether or not the after dashpot timer is 0. When the timer after dashpot is 0, the NFB flag is set and the process returns to step S2. If the timer immediately after the idle switch is turned on is not 0 in step S30, the vehicle speed pulse timer is not 0 in step S31, the after cooler on timer is not 0 in step S33, the after cooler off timer is not 0 in step S34, or in step S35. If the timer after dashpot is not 0, the process proceeds to step S29, resets the NFB flag, and returns to step S2. Therefore, a predetermined time or more has elapsed since the idle switch 9 was switched from off to on, the timer immediately after the idle switch was turned on was 0, the vehicle speed pulse timer was 0 (2.0 km / hour or less), and the vehicle speed pulse timer was 0. A predetermined time has elapsed since the cooler switch 20 was switched, the timer after turning on the cooler switch was 0 when the cooler switch 20 was on, and the timer after turning off the cooler switch was 0 when the cooler switch 20 was off. The NFB flag will be set if all the conditions that the post dash pot timer is 0 after the end of the pot have passed and the NFB flag will be reset if any of these conditions are not met. .

Further, the control unit 15 includes a timer countdown routine, a vehicle speed detection routine,
The actuator drive routine in NFB control and the actuator drive routine in throttle valve position feedback (PFB) control are executed by interrupt processing.
In the timer countdown routine, as shown in FIG.
By the interrupt request signal every 50 msec, each of the timer count immediately after the idle switch is turned on, the vehicle speed pulse timer, the timer after the cooler on, the timer after the cooler off, and the timer after the dashpot is subtracted (-1), and the count after subtraction becomes negative. Then, the count value of the timer is held at 0 and the counter K is incremented (+1). In the vehicle speed detection routine, the ninth
As shown in the figure, each time a vehicle speed pulse is sent from the vehicle speed sensor 22, a predetermined count number is set in the vehicle speed pulse timer.

10th in the actuator drive routine in NFB control
As shown in the figure, the NFB flag is checked by an interrupt request signal every 1 second, NFB control is executed when the NFB flag is set, that is, the target rotation speed NS and the actual rotation speed NR based on the detection signal from the engine speed sensor 12 The difference ΔN is obtained, and the drive time ΔD of the motor 5 corresponding to the difference ΔN is calculated. Next, this time ΔD is set in the motor timer and the motor timer is triggered to drive the motor 5 until the motor timer becomes zero.

Furthermore, in the actuator drive routine in PFB control, as shown in Fig. 11, N is generated by an interrupt request signal every 100 msec.
Check the FB flag and perform PFB control when the NFB flag is reset. That is, the difference ΔP between the target position PS and the actuator actual position PR based on the detection signal from the motor position sensor 8
Until the motor timer becomes 0 by calculating the drive time ΔD of the motor 5 according to this difference ΔP, setting this time ΔD in the motor timer and triggering the motor timer. The motor 5 is driven.

When ΔD is positive, the rod 7 is advanced, and when ΔD is negative, the rod 7 is retracted. The relationship between ΔP, ΔN and ΔD is set as shown in FIGS. 5 (a) and 5 (b).

FIG. 3 is a timing chart showing an operation example of this embodiment.

In this embodiment, the dashpot control is performed by the idle switch ON and PFB control (steps S10, S21 to S2).
3) and the initial opening of the dashpot is set according to the engine load condition (throttle valve opening) (step S1
5) and update only when increasing (steps S16, S1)
7). Then, by knowing the actual position PR of the actuator and performing PFB control (see Fig. 11), it is possible to set the optimal dashpot initial opening for any load condition during off-idle, and to reduce the engine load condition. When the load on the vehicle is reduced, the fine dashpot operation can be performed, and the shock to the vehicle body can be reduced. Furthermore, when the load is reduced from the medium load state, the dashpot operation can be performed only in accordance with the load at that time, the degree of engine braking and the fuel consumption are improved. Moreover, the engine output does not increase during deceleration from the low load range.

FIG. 13 shows the main routine of the second embodiment of the present invention.

In this second embodiment, the main routine of the control unit 15 in the above embodiment is modified as shown in FIG.
And wait time timer LT in the timer countdown routine
The countdown of is also done. The control unit 15 in the second embodiment proceeds from step S4 to step S11 in the main routine of FIG.
From step S15 to step S37, the dashpot initial opening waiting time TDP is detected by the detection signal from the throttle sensor 21, and the value TDP (θ
R). Here, the relationship between the dashpot initial opening waiting time TDP and the throttle valve opening θR is proportional to the amount of the dashpot initial opening waiting time TDP being a certain value or more of the throttle valve opening θR as shown in FIG. Is set and stored in ROM. Next, in step S38, the dashpot flag L is checked, and if the flag L is reset, the counter K is reset in step S39 and the process proceeds to step S16. If the flag L is set, the standby time timer LT is set in step S40. Check if is zero. If the standby time timer LT is not 0, the counter K is reset at step S39 and the process proceeds to step S16. If the standby time timer LT is 0, at step S21 the predetermined opening ΔD × K is set from the dashpot initial opening MDP. Subtract and proceed to step S16. From step S17 to step S14, after setting the dashpot initial opening standby time TDP to the standby time timer LT, the process proceeds to step S18, and from step S16, S18 to step S5, from step S6, S9 to step S5.
Proceed to 22.

Therefore, in the second embodiment, the subtraction of the dashpot initial opening degree is performed while waiting for the dashpot initial opening degree waiting time TDP. FIG. 12 is a timing chart showing an operation example of the second embodiment.

In the above embodiment, the dashpot operation was performed by detecting that the load condition of the engine was lower than the load condition corresponding to the target position of the actuator, but it was detected that the load condition of the engine became the low load condition. Alternatively, the dashpot may be operated.

As described above, according to the present invention, the target position of the actuator is set according to the load state of the engine and the dashpot operation is performed using the actual position information of the actuator. It is possible to set the optimal dashpot initial opening for the state, and it is possible to perform a fine dashpot operation when the load from the high load state of the engine is reduced, and to reduce the shock to the vehicle body. Furthermore, when the load is reduced from the medium load state, the dashpot operation can be performed only according to the load at that time, the degree of engine braking, the fuel consumption improves,
Moreover, the engine output does not increase during deceleration from the low load range. Further, since the actuator is held even when the throttle valve is disengaged from the actuator, the fully closed position of the throttle valve can be made to accurately follow the target position even during off-idle, and the fully closed position of the throttle valve is achieved. The opening immediately after does not deviate from the planned value.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of the present invention, FIG. 2 is a schematic diagram showing an embodiment of the present invention, FIG. 3 is a timing chart showing an operation example of the same embodiment, and FIGS. Is a characteristic diagram for explaining the same embodiment, FIG. 7 is a flow chart showing a main routine of the control unit in the same embodiment, and FIGS. 8 to 11 are flow charts showing respective interrupt routines of the control unit. FIG. 12 is a timing chart showing an operation example of the second embodiment of the present invention, FIG. 13 is a flow chart showing a main routine of the control unit in the second embodiment, and FIG. 14 is for explaining the second embodiment. FIG. 101 ... Intake flow control valve, 102 ... Actuator, 103
…… Holding means, 104 …… Idle detection means, 105 …… First
Control means 106, load detection means 107, target position setting means 108, second control means 109, third control means.

Front Page Continuation (72) Inventor Yoshitaka Yoshida No. 1 Nakashinri, Hashime-cho, Okazaki, Aichi Prefecture Mitsubishi Motors Corporation, Passenger Car Technology Center (72) Inventor Kazutoshi Noma Nakashinri, Hashime-cho, Okazaki, Aichi Prefecture No. 1 in the Passenger Car Technology Center, Mitsubishi Motors Corporation (56) References Japanese Patent Laid-Open No. 59-231160 (JP, A)

Claims (1)

[Claims] 1. A throttle valve provided in an intake passage of an engine, and an actuator which is provided so as to be engageable with and disengageable from the throttle valve and variably sets a fully closed position of the valve to control the opening degree of the valve. Idle detection means for detecting whether or not the throttle valve is in the fully closed position, and when the idle detection means detects that the throttle valve is in the fully closed position and other set conditions are satisfied. First control means for supplying a control signal to the actuator so that the engine speed becomes a desired idle speed; target position setting means for setting an actuator target position according to the operating state of the engine; Holds actual position information about the actuator both when the throttle valve is in the fully closed position and when it is released from the fully closed position. The holding means and the target position set by the target position setting means and the holding means when the throttle valve is at the fully closed position and when the throttle valve is separated from the fully closed position when the setting condition is not satisfied. Second control means for supplying a control signal to the actuator so that the position of the actuator becomes the target position by comparing the held actual position information, and load detection means for detecting the load state of the engine. The target position setting means is based on the detection result of the load detection means, the fully closed position as the engine load increases in the off idle load state corresponding to the disengaged state of the throttle valve from the fully closed position. The target position is set in order to make the load larger and the load condition of the engine is less than the load condition corresponding to the target position. The intake air of the engine is configured to set the target position so as to gradually displace the throttle valve to the closing side when the load condition of the engine becomes a low load condition. Quantity control device.