JPS63150447A - Number of idle revolution control device for engine - Google Patents

Abstract

PURPOSE:To perform smooth shifting of a starting state to an idling state, by a method wherein an air mount added during starting is gradually decreased, an amount equivalent to a decrease amount of air for starting is set as a fundamental amount of feedback control during shift of a starting state to an idling state. CONSTITUTION:A control device is provided with a means B, regulating an intake air amount fed to a combustion chamber A, a means C, performing feedback control of an intake air amount so that the number of revolutions of an engine is converged to the target number of revolutions during idling, and a means D, adding a given amount of air for starting during starting. In this constitution, The means U is formed such that an amount of additional air is gradually decreased after starting. A means E, which, during shift of a starting state to an idling state, sets an amount, being equivalent to a decrease amount of air for starting from a shifting point of time, as a fundamental amount of feedback control, is provided. Feedback control is effected by the means C based on an amount obtained by adding a fundamental amount, set by the means E, to a remaining amount of air for starting.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an engine idle speed adjustment system, particularly an engine which is configured to add a predetermined amount of starting air at the time of starting, from a starting state to an idling state. This invention relates to a rotational speed control ON device during transition.

(Prior Art) In order to improve the fuel efficiency and exhaust performance of automobile engines, the amount of intake air is adjusted during idling, as shown in, for example, Japanese Patent Laid-Open No. 54-98413. Feedback control of the idle speed is performed to a predetermined target speed, but in addition to such feedback control during idle, the supply of starting air is controlled when starting the engine to improve startability. It may happen. As shown in Fig. 9, this control at the time of starting is performed by setting the target rotation speed N at the time of starting (when the ignition key is turned on).
In addition to the basic air ffH corresponding to o, a predetermined amount of starting air (2) is supplied, and when the engine speed N exceeds the target rotation speed No, the amount of starting air (2) is gradually reduced. Then, when the starting air (2) becomes zero, feedback control is started by supplying the feedback control air (2) according to the deviation between the target rotational speed NO and the actual rotational speed N.

(Problems to be Solved by the Invention) However, according to the control at the time of starting as described above, the preset basic air II and the target rotation speed No. do not necessarily correspond to each other due to variations in the engine itself or operating conditions, etc. Therefore, as shown in Fig. 9, the actual rotation speed N is changed to the target rotation speed N.
In some cases, a large amount of feedback control air ■ may be required to converge to the target rotation speed No. a bigger decline,
If this is significant, a problem arises in which the engine stalls.

To deal with this, as shown in Fig. 10, when the engine speed N once exceeds the target speed No. and then decreases to the target speed No. again, the supply of starting air is stopped and feedback is provided. At the same time as starting the control, the amount of starting air ■' at that time is supplied as the basic amount ■' of feedback control, and the actual rotation speed N is made to converge to the target rotation speed No based on this basic amount ■'. It is conceivable to perform feedback control. However, even in this case, since a certain upper limit is set for the amount of air supplied by the feedback control, as shown by the chain line A in FIG. Starting air at start ■
′ may not be possible, and in this case, due to insufficient air supply m, the engine speed N may decrease as shown by the chain line.
will fall.

The present invention provides an engine that performs feedback control to converge the engine speed at idle to a target rotation speed and control for supplying starting air at the time of starting, when the engine speed changes from the starting state to the idling state. The purpose of this invention is to deal with the above-mentioned problems and prevent the engine speed from dropping and stalling during this transition.

(Means for Solving the Problems) That is, the engine idle speed control device according to the present invention includes an intake air m adjusting means for adjusting the amount of intake air supplied to the combustion chamber A, as shown in FIG. B, feedback control means C for feedback controlling the intake air amount by the intake air m adjusting means B so as to converge the engine speed to the target rotation speed during idling, and a starting system for adding a predetermined amount of starting air at the time of starting. In the configuration provided with the air adding means, the starting air adding means is configured to gradually reduce the amount of air added at the time of starting after starting, and when transitioning from the starting state to the idle state, Feedback basic total setting means E is provided for setting the reduced amount of the starting air from the point of transition as a basic amount of feedback control, and the feedback control means C
However, during the transition to the idle state, the basic ω setting means E
The present invention is characterized in that the feedback f and lI control is carried out based on the basic amount set in , which is added to the remaining amount of starting air.

(Function) According to the above configuration, good starting performance is obtained by the starting air supplied by the starting air adding means at the time of starting, and the amount of starting air is reduced after starting, thereby increasing the engine rotational speed. When the engine reaches the target rotational speed and shifts to the idle state, this reduced amount of starting air is supplied as the basic amount for feedback control, so after the shift to the idle state, the basic amount is used as the remaining starting air. Air added to the amount of air, that is, an amount of air equal to the amount of starting air at the time of transition to the idle state, will continue to be supplied thereafter. Then, feedback control will be started based on this suspension, but since this m is the mother corresponding to the engine rotation speed at the time of transition to the idle state, that is, the target rotation speed, at the start of feedback control always The amount of air necessary to maintain the target rotational speed is supplied as a reference amount, so the amount that serves as the reference for feedback control may be insufficient, and the feedback control to compensate for this shortage may be delayed. This will prevent the engine speed from dropping and stalling due to this.

(Example) Examples of the present invention will be described below.

FIG. 2 shows the engine control system according to this embodiment. The engine 1 is provided with an intake passage 5 and an exhaust passage 6 that communicate with the combustion chamber 4 via intake and exhaust valves 2 and 3. , an air cleaner 7 is connected to the intake passage 5 from the upstream side,
An air meter 8, a throttle valve 9, and a fuel injection valve 10 are arranged in the exhaust passage 6, and the air-fuel ratio of the mixture being supplied to the combustion chamber 4 is determined from the residual oxygen concentration in the exhaust gas from the upstream side. The engine is equipped with an 02 sensor 11 and an exhaust purification device 12 that detect whether the fuel ratio is lean (a state where the fuel ratio is low) or rich (a state where the fuel ratio is high).

Further, the intake passage 5 is provided with a bypass passage 13 that communicates the upper and downstream sides of the throttle valve 9, and a bypass air control valve 14 is provided on the bypass passage 13 to adjust the amount of bypass air passing through the passage 13. is set up.

The engine 1 is equipped with a control unit 20 that controls the amount of fuel injected from the fuel injection valve 10 and the amount of bypass air passing through the bypass passage 13 during startup or idling. This control unit 20 controls the intake air bias @a from the air 70-meter 8 and a sensor 21 that detects the engine speed.
When the engine speed signal from
the air-fuel ratio signal C from the engine 1, the water temperature signal d from the water temperature sensor 22 that detects the cooling water temperature of the engine 1, and the air cleaner 7 and air 70-me in the intake passage 5.

The intake temperature signal e from the intake temperature sensor 23 installed between the intake temperature sensor 23 and the intake temperature sensor 23 is inputted. The fuel injection valve 10 and the bypass air control valve 14 are configured to control the fuel injection m and the amount of bypass air according to the values indicated by these signals a to e.
The control signals f and Q are outputted to the control signals f and Q, respectively.

Here, the outline of the fuel injection port control by the control unit 20 will be explained.
The amount of air taken into the combustion chamber 4 per cycle is calculated, and the corresponding basic fuel injection amount is set, and this value is used to increase the amount when the air-fuel ratio indicated by the signal C from the 02 sensor 11 is lean. And when it is rich, it is corrected by subtraction,
Furthermore, after performing other corrections, the final injection radius is determined. And, so that this final jet reaches 01m, i! The f1all signal f is output to the fuel signal valve 10.

On the other hand, control of the bypass air 9 during starting or idling, which is a characteristic part of the present invention, is performed as follows according to the flowchart shown in FIG.

In other words, the control unit 20 first performs step S in the flowchart when the ignition key is turned on.
1 to step S2, and the above signals s, d, eIP
- Based on the engine speed N, water ITw and intake mTa are read. Then, in step S3, the fourth
As shown in the figure, the base air lQo of the bypass air is set based on the preset characteristics, and in step S4, the initial 1fllQw o and Qa o of the bypass air water temperature correction ωQw and the intake air temperature correction mQa are set as 5.6. Each setting is made based on preset characteristics as shown in the figure. Here, in order to promote warm-up during startup or idling,
The lower the water mTw is, the larger the base air IQo of the bypass air and the initial gnQWo of the water temperature correction amount are set. Further, the initial value Qaq between intake temperature supplements is set to a larger value as the intake air temperature Ta is higher, in order to ensure the required filling amount.

Next, in step S5, the control unit 20 determines whether the actual engine rotation speed N is greater than or equal to the target idle rotation speed N0. As shown in FIG. 7, this target rotational speed No. is also set to a higher value as the water temperature TW is lower, in order to promote warm-up. Immediately after starting, when the actual rotational speed N is lower than the target rotational speed No, that is, when it is in the starting zone shown in FIG. 8(a), the total bypass air fjltQ is calculated in step S6. That is, in this starting zone, the bypass air IQ is the base air ff1Qo.
is the sum of the water temperature and intake air correction IQW, Qa (these correction amounts are collectively referred to as the starting correction amount), but in this case, the above corrections ff1QW and Qa are the respective initial values Q
Since w o and Qa o, the starting correction m is the 8th
As shown in Figure 8(b), QVI o + Qa o, and the total bypass air liQ is equal to this start-up correction ffl (QW o + Qw) as shown in Figure 8(d).
o ) to the above base air lQo.

In the starting zone, this air 1 (Qo+QV
A control signal g is output to the bypass air control valve 14 so as to be fixed at I o +Qa o ).

Then, when the actual rotation speed N increases due to the above-mentioned amount of bypass air and becomes equal to or higher than the target rotation speed No, the control unit 20 moves from step S5 to step S7. S
Execute step a to correct the water temperature at startup ff1QW (initially Q
w o ) and intake temperature correction mQa (initially Qa o )
The minute amounts AQVI and AQa are repeatedly subtracted from , and as a result, these laQ'll
, Qa is a negative value, QW = O, Qa = O. Then, while the actual rotational speed N is greater than or equal to the target rotational speed No, steps S9 to S6 are executed. As a result, the starting correction Ji (Qw +Qa) or the total air IQ, which is the addition of the base air amount Qo, is as shown in Fig. 8(b).

As shown in (d), ω gradually decreases from the starting zone. As a result, the actual rotation speed N, which once exceeded the target rotation speed No, decreases as shown in FIG.

In this way, the bypass air starting correction amount (QW
+Qa), the actual rotational speed N becomes equal to or lower than the target rotational speed No, and when the operating state shifts from the starting state to the idle state, the control unit 20 next performs step S.
1o - Feedback control of bypass air IQ is started according to -812. In this feedback control, first, in step S10, the deviation ΔN (-N-No) of the actual rotation speed N from the target rotation speed NO is determined,
In step S11, feedback control mQf is calculated. In that case, the control unit 20 controls the feedback υ control amount to increase the correction value of the starting correction 1 (QW+Qa), which increases in accordance with the decrease of 1 minute from the value (QW 1+Qa + ) at the time of transition to the idle state [1]. Qf
The sum of this basic IQfo and the gain amount -Qf for eliminating the above-mentioned deviation JN is set as the feedback control JIQf. Then, in step S12, the base air flQO and the starting correction ff
l (QW +Qa) and the above feedback control f
f1Qf (Qf o + AQ, f ) is added to calculate the total air σQ, and the control signal g is output to the bypass air control valve 14 so that the air becomes fmQ.

In this way, feedback control of the bypass air is started from [1] at the time of transition to the idle state. In that case, it depends on this feedback till that the remaining amount of the starting correction fi (Qw + Qa) after the time t1 transition to the idle state is changed to m (QW + +Qa1) at the time t1 of the starting correction amount. ) is used as the reference amount, which is the amount of feedback basic mQro added, which is equal to the reduction from The reduction will begin with a constant amount equal to the starting correction amount at the end of the zone. And this i (Qw + +Qa
+ ) is the amount when the engine rotation speed N becomes equal to the target rotation speed No, so the engine rotation speed N shifts to the idle state without falling significantly below the target rotation speed No, and from then on, the actual rotation speed Feedback control is performed so that the actual rotational speed N is maintained converged to the target rotational speed No by increasing or decreasing the gain mAQf according to the deviation AN between N and the target rotational speed NO.

(Effects of the Invention) As described above, according to the present invention, in an engine that performs feedback control for converging the idle speed to the target speed and controls the supply of starting air at the time of starting, the feedback control During the transition from the starting state to the idling state, the engine speed drops below the target speed due to insufficient air being supplied to the combustion chamber and a delay in the response of feedback control to compensate for this. This eliminates the occurrence of a large drop or engine stall, and the transition from startup to idling operation in this type of engine is always performed smoothly and favorably.

[Brief explanation of the drawing]

Fig. 1 is an overall configuration diagram of the present invention, Figs. 2 to 8 show embodiments of the invention, Fig. 2 is a control system diagram, and Fig. 3 is a flowchart showing control operations. Figs. 4 to 7 are graphs showing the characteristics of base air amount water temperature correction amount initial value, intake temperature correction amount initial value and target rotation speed used for control, respectively, with respect to water temperature or intake temperature, FIG. 8 is an engine rotation speed showing the effect,
FIG. 3 is a time chart of a starting correction amount, a feedback basic amount, and a total bypass air amount. Also, Section 9.1
FIG. 0 is a time chart diagram showing conventional control examples and their problems. 4... Combustion chamber, 14... Bypass air υJl valve (intake air amount adjusting means), 20... Control unit (feedback control means, starting air addition means, feedback basic amount setting means). Figure 3 - Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 10

Claims (1)

[Claims] (1) An intake air amount adjustment means that adjusts the amount of intake air supplied to the combustion chamber, and feedback control of the intake air amount by the intake air amount adjustment means so that the engine speed converges to the target rotation speed during idling. An engine idle speed control device comprising a feedback control means and a starting air adding means for adding a predetermined amount of starting air at the time of starting, wherein the starting air adding means controls the amount of air added at the time of starting. Feedback basic amount setting is configured to gradually reduce the amount of starting air after starting, and at the time of transition from the starting state to the idling state, the amount of reduction in the starting air from the point of transition is set as the basic amount of feedback control. means is provided, and the feedback control means performs feedback control based on the amount obtained by adding the feedback basic amount set by the feedback basic amount setting means to the remaining amount of the starting air during transition to the idle state. An engine idle speed control device, characterized in that it is configured to perform the following.