JPS6196154A - Idling speed controller for engine - Google Patents

Abstract

PURPOSE:To make stable idling speed control come to fruition, by compensating a span of energizing time to an idling speed controlling solenoid-operated device, varying its operating mode according to battery voltage to be changed by consumption or the like, according to the battery voltage. CONSTITUTION:In case of a device which installs a bypass passage 14, bypassing a throttle valve 12, is installed in a suction passage 10 and controls an idling speed in a way of duty-controlling a solenoid valve 15 installed in the said passage 14, the solenoid valve 15 is controlled by a control unit 16. That is to say, each output signal out of various running state detecting devices 11, and 17-19 and a voltage sensor 20 detecting battery voltage is taken in, and when first it is judged as an idle running state, a basic compensation term is calculated. Next, both maximum and minimum values of the battery voltage are read, calculating the mean value, and a sudden change in the battery voltage is detected with this mean value. And, in time of the sudden change of the battery voltage, a final compensation term is calculated with the voltage compensation factor prior to the said sudden change whereby the solenoid valve 15 is controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an engine idle speed control device.

(Prior art) As shown in Japanese Patent Laid-Open No. 55-156230, some engine idle speed control devices include electromagnetic means for adjusting the idle speed of the engine, and are capable of adjusting the actual engine speed and idle target speed. There is an engine in which the idle speed of the engine is set to the idle target speed by controlling the energization to the electromagnetic means based on the rotational deviation of the engine, that is, by using feedback control. In a gasoline engine, the electromagnetic means is, for example, a solenoid valve that adjusts the amount of intake air, and the energization is controlled by, for example, duty control. In other words, when the electromagnetic stage is a solenoid valve for adjusting the amount of intake air, the amount of intake air is adjusted by adjusting the opening degree of this solenoid valve using duty control.
The idle speed of the engine will be adjusted.

By the way, in the case of a car, the power source is a battery, so
There is a possibility that the operation mode of the electromagnetic means will differ depending on the magnitude of the battery voltage, and therefore, it has been considered to correct the energization time to the electromagnetic means according to the magnitude of the battery voltage. That is, electromagnetic means typically
Although it operates without any problem in response to slight fluctuations in the predetermined battery voltage, the battery voltage may drop significantly due to, for example, worn-out battery packs or use in cold regions. If this battery voltage decreases significantly, when the electromagnetic means is operated at a predetermined duty ratio, the duty ratio will become substantially smaller, and there is a possibility that the idle speed of the engine will not be adjusted as desired. .

To explain this point in detail, the battery voltage is generally 12V in the case of a passenger car, for example, but if it is 11V or higher, the rise of the pulse due to duty control is shown in Figure 4 (
Even if the predetermined duty ratio, e.g., A%, is accurately obtained as a result of performing the process quickly as shown in a), if the battery voltage drops to, for example, IOV, as shown in FIG. 4(b). As shown in the figure, the rise of this pulse is delayed, and even though the duty ratio appears to be A%, it is actually A%.
Therefore, the apparent duty ratio becomes A+α%, which is larger than A%.
By correcting the energization time to the electromagnetic means, the actual A%
It is considered to obtain a duty ratio of

However, when realizing something like this, if the energization time to the electromagnetic means is simply corrected according to the battery voltage, rapid fluctuations in the battery voltage will be picked up and this will interfere with the control of the idle rotation speed. It turns out that there is a risk.

To explain this point in detail, 1. For example, when an air conditioner is activated, the battery voltage temporarily drops significantly at the same time as the activation, as shown in FIG.

Therefore, due to such a sudden voltage change, the energization time to the electromagnetic means changes greatly in a short period of time.
The control response delays (for example, the change delay in intake air) do not match well, resulting in the engine's idle speed becoming unstable.

(Object of the invention) The present invention has been made in consideration of the above circumstances, and
When correcting the energization time to the electromagnetic means for adjusting the idle speed according to the battery voltage, this device compensates for the sudden fluctuations in the battery voltage and stably maintains the idle speed at the target idle speed. The object of the present invention is to provide an idle speed control device for an engine.

(Structure of the Invention) In order to achieve the above-mentioned object, in the present invention, when the pantalli voltage suddenly changes, the energization mode to the electromagnetic means is corrected.
This should not be done based on the battery voltage at the time of the sudden change.

Specifically, as shown in Figure 1, it is equipped with electromagnetic means for adjusting the idle speed of the engine,
The idling speed of the engine is controlled to become the idle target speed by controlling the energization of the 'rL magnetic hand pitching means based on the rotational deviation between the actual engine speed and the idle target speed. The idle speed control device for an engine includes: a voltage detection means for detecting a battery voltage; and an energization correction means for receiving an output from the voltage detection means and correcting a mode of energization of the electromagnetic means according to the battery voltage. , a voltage sudden change detection means for detecting a sudden change in the battery voltage; and receiving an output from the voltage sudden change detection means and not causing correction of the energization mode based on the sudden change in battery voltage when the battery voltage suddenly changes. and energization correction means.

This is assumed to be equipped with the following.

The contents up to the top of the above premise, that is, the contents of the feed pack control, are well known in the art, and are therefore collectively shown as basic control means in FIG.

(Example) Embodiments of the present invention will be described below with reference to the accompanying drawings.

In FIG. 2, l is an engine body, in which a combustion chamber 5 is defined by a cylinder block 2 and a cylinder head 3 and a left piston 4, and a crankshaft (not shown) is rotationally driven by the reciprocation of the piston 4. It is said to be a response-response type. An intake port 6 and an exhaust port 7 are respectively opened in the combustion chamber 5, and the intake port 6 is opened by an intake valve 8, and the exhaust port 7 is opened by an exhaust valve 9 in synchronization with the rotation of the crankshaft. It opens and closes at the right time.

In the intake passage lo connected to the intake port 6, an air cleaner (path shown), an air flow meter 11, a throttle multi-torque valve 2, and a fuel injection valve 13 are disposed in order from the upstream side (atmospheric side).

The intake passage 10 is provided with a bypass passage 14 that bypasses the throttle valve 12, and a solenoid valve 15 whose opening degree is adjusted by duty control is connected to the bypass passage 14. Of course, this bypass passage 14 is for flowing intake air for adjusting the idle rotation speed during idling, and the amount of intake air is adjusted by the solenoid valve 15. Of course, this electromagnetic valve 15 constitutes electromagnetic means for adjusting the idle rotation speed.

Reference numeral 16 in FIG. 2 is a control unit, and the signal S, -55 is inputted to the control unit 16, and the signal S, -55 is outputted from this control unit 16 to the fuel injection valve 13 and the electromagnetic valve 15. It has become so. Of the signals S and -SS, the signal S1 is from the air flow meter 1 and corresponds to the amount of intake air. The signal S2 is from the throttle sensor 7 and corresponds to the throttle opening. The signal S is from the rotational speed sensor 8 and corresponds to the engine rotational speed (actual rotational speed). The signal S4 is from the load switch 19 and is used to detect that the load on the engine has been activated, such as when the air conditioner is activated or when the automatic transmission tower tank is set to the driving range. Signal S5 is from voltage sensor 20 and corresponds to the battery voltage.

The control unit 16 receives an intake air amount signal S1.
In addition to controlling the amount of fuel injected from the fuel injection valve 13 in a well-known manner, the solenoid valve 15 is also controlled based on the engine speed signal S and the engine speed signal S.

To explain the control of the solenoid valve 15 by the control unit (control unit) 16, the solenoid valve 15 is opened only during idle detour, and the bypass passage 15 is opened depending on the engine operating mode.
This control unit adjusts the intake air amount from 4 to control the idle speed of the engine to become the idle target speed.
The energization mode is corrected according to the battery voltage. That is, in the embodiment, the opening degree of the solenoid valve 15 is adjusted by duty control (the amount of intake air is adjusted).
As the duty ratio increases, the opening degree increases and the idle rotation speed is corrected to the upward side. According to the present invention, when the battery voltage is greatly reduced due to battery exhaustion or use in a cold region, the rise of the pulse for duty control is delayed and the desired opening is not reached. In order to compensate for the inability to accurately obtain the desired duty ratio, the energization time to the solenoid valve 15 is corrected in accordance with the battery voltage in order to compensate for the difference in battery voltage, that is, the difference in the rising edge of the pulse. It's Nishide.

The control unit 16 that performs the above-mentioned control is
For example, it is configured by a microcomputer, and a specific example of its control will be described below with reference to the flowchart shown in FIG.

In this flowchart, since the idle target rotation speed is feedback-controlled, the duty ratio for duty-controlling the solenoid valve 15 includes the basic duty ratio DB, the actual engine rotation speed, and the target idle speed. A duty ratio DFB for feedback corresponding to the rotational deviation from the target rotation speed is set, and a duty ratio DL for load correction is set in order to perform correction based on the load on the engine such as an air conditioner. The voltage correction is performed on the total of the duty ratios DB, DFB, and DL. Furthermore, if the battery voltage suddenly changes due to, for example, the activation of an air conditioner, the above-mentioned energization correction to the electromagnetic means is not performed based on the sudden change in battery voltage. This makes it possible to quickly detect whether or not the battery voltage has changed suddenly by checking whether or not a load on the engine, such as an air conditioner, that is the cause of the sudden change has been activated.

Based on the above, first, in step S1,
The engine speed (actual speed) N and throttle opening are read, and step S
In step 2, it is determined whether the vehicle is in an idling state. If it is determined in step S2 that the vehicle is not in an idling state, the process returns to step S1, and if it is determined that the vehicle is in an idling state, the process proceeds to step S3, where a basic correction term DB is calculated.

After that, in step S4, it is determined whether or not a load on the engine, such as an air conditioner, has been activated.

When this load is not operating (load switch 19 is
FF), the flag is set to O in step S5, and the load correction term DL is set to O in step S6, and then the process proceeds to step 514.

In addition, the load switch 19 is activated (ON) in step S4.
When it is determined that the switch is turned on, it is determined in step S7 whether or not this is the moment when the switch is turned on. And O
If it is the moment when the load is turned on, the flag is set to 1 in step S8, and the timer T is set to a predetermined period of time A in step S9. After calculating the load correction term DL, the step S
Move to L4.

On the other hand, when it is determined in step S7 that the moment when the load switch 19 is not turned on, step Sll
Then, it is determined whether or not the timer T set in step S9 has reached O. Load switch 19 is O
Immediately after being rejected.

Since the timer T has not yet counted down to O, the process moves to step S12 and counts down the timer T. After this countdown is completed, the process moves from step Sll to step S13, and in step S13, the flag is flagged. After setting O to O, the step 510
Move to.

In step 314, the target rotational speed N is calculated according to the operating state of the engine, for example, the warm-up state. Then,
In step 515, it is determined whether the actual engine rotation speed N is larger than the upper limit range of the idle target rotation speed (CN O + α), which is the target rotation speed No. plus a predetermined rotation speed α (for example, 50 rpm). . This step S1
In the determination in Step 5, if NO+α≦N, the actual rotational speed is too high, so in order to correct this, step S16
, a predetermined (previous) feedback correction term DF
After subtracting ΔDFB from B and setting it as a new feedback correction term DFB, the process moves to step S19. Also, in step 515 above, No+
If α≦N, if it is determined that there is no
, No-α is the lower limit range of the target idle rotation speed.
, it is determined whether N is small or not. If No-α≦N, the actual rotation speed is too low. In order to correct this, in step 318, a predetermined (previous) feedback correction term DFB is set. After adding ΔDFB to ΔDFB is newly set as the feedback correction term DFB, step S1
Move to 9. Then, in step S17, the result is N. −
When it is determined that α≦N, the actual engine speed is within the allowable range of the target idle speed (No-
α＜NUN. +α), so in this case, the process directly advances to step S19.

In step S19, the maximum value V MAX and minimum value V MIX of the battery voltage are read. Next, in step S20, the average value V of the battery voltage
AVE is calculated. In this embodiment, this average value V AVE is the arithmetic average of V MAX and V old in step S12, plus the previous V AVE, and then the arithmetic average of . Thereafter, in step s21, it is determined whether the flag is 1 or not, that is, a certain period of time after the load switch 19 where the battery voltage suddenly changes is turned on and the battery voltage that suddenly changes converges to the original stable state (step S9 It is determined whether or not the set time (time set in ) has elapsed. When it is determined that this flag is not 1, the battery voltage is not changing suddenly, so in step 322, a battery correction term (correction coefficient) CVAT is calculated based on WAVE obtained in step 52G. Finally, in step 523, the DB (basic) and DL (
The battery correction term CVAT is multiplied by adding the load) and DFB (feedback) to calculate the final correction term, and a pulse with a duty ratio corresponding to this final correction term is calculated. However, in step 24, solenoid valve 1
5 is output. Of course, the larger the final correction value is, the larger the opening degree of the electromagnetic valve 15 is, that is, the larger the amount of intake air flowing through the bypass passage 14 is, and the engine speed is controlled to increase.

On the other hand, when it is determined in step S21 that the flag is 1, the process directly proceeds to step S23 without passing through step 522. In other words, when the flag is 1, it means that the battery voltage is changing suddenly, so the final correction value is calculated using the voltage correction coefficient CBAT before the sudden change, without using the battery voltage at this time. Become.

Note that the battery correction term CBAT is set to 1 when the voltage is equal to or higher than a predetermined voltage that does not cause a delay in the rise of the pulse due to duty control, and is set to increase as the battery voltage becomes smaller than this predetermined voltage. Set.

Note that the process in steps S19 and S20 is performed to compensate for subtle fluctuations 6 in battery voltage due to subtle fluctuations in engine speed. That is, while the battery voltage is being charged by the alternator driven by the engine, the engine speed is subject to essentially periodic fluctuations due to the intermittent explosion stroke. Therefore, the battery voltage fluctuates over a very short period of time. If there is a difference in the rise of the pulse due to the above-mentioned duty control within the range of this battery voltage fluctuation, the energization time for the electromagnetic means will be repeatedly and frequently corrected, and this will affect the control response. This is likely to cause the idle speed to become unstable due to a delay (for example, a delay in changing the amount of intake air), but step 319.20
This problem can also be solved by processing.

In the embodiment, the maximum value and minimum value in step 319 are determined so that at least one period of variation in battery voltage due to variation in engine speed can be detected. It is determined (selected) from an appropriate number of samples sampled at each predetermined period (for example, at every predetermined time or every predetermined crank angle).

Although the embodiments have been described above, the present invention is not limited thereto, and includes, for example, the following cases.

(2) The intake air amount may be adjusted by adjusting the opening degree of the throttle valve 12 using electromagnetic means without providing a separate bypass passage.

L■ This can also be applied to diesel engines; in this case, for example, the governor position corresponding to the fuel injection amount of the fuel injection pump may be adjusted by electromagnetic means (
For example, see Japanese Patent Application Laid-Open No. 57-97027).

(■Even when the battery voltage suddenly increases (for example, when the load switch 19 is turned off), the same process as when the battery voltage suddenly drops as described in the embodiment may be performed. When the battery voltage suddenly increases, the effect is relatively smaller than when the battery voltage suddenly decreases, but it is more preferable in order to obtain a stable idle rotation speed.

(Effects of the Invention) As is clear from the above description, the present invention adjusts the energization time to the electromagnetic means whose operation mode changes according to the battery voltage that changes due to consumption etc. in accordance with the magnitude of the battery voltage. Since the correction is carried out, it is possible to obtain a favorable result in stably maintaining the idle rotation speed at the idle target rotation speed.

In addition, if the battery voltage suddenly changes, the energization correction to the electromagnetic means described above is not performed based on the battery voltage at the time of the sudden change, so the idle speed can be stabilized at the idle target speed. This results in an even more preferable solution for maintaining the temperature.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram of the present invention. FIG. 2 is an overall system diagram showing one embodiment of the present invention. FIG. 3 is a flowchart showing one control example of the present invention. FIGS. 4(a) to 4(c) are diagrams showing differences in the manner in which control pulses are supplied to the electromagnetic means based on differences in battery voltage, and correction of the energization time to compensate for this difference. FIG. 5 is a diagram showing how the battery voltage suddenly changes. 1: Engine body lO: Intake passage 14: Bypass passage 15: Solenoid valve 16: Control unit 20: Voltage sensor □ Email
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Claims (1)

[Claims] (1) An electromagnetic means for adjusting the idle speed of the engine is provided, and the idle speed of the engine is controlled by controlling the energization to the electromagnetic means based on the rotational deviation between the actual engine speed and the idle target speed. The engine idle speed control device is configured to control the engine idle speed so that the engine speed becomes a target idle speed, comprising: voltage detection means for detecting a battery voltage; energization correction means for correcting the energization mode to the electromagnetic means; voltage sudden change detection means for detecting a sudden change in the battery voltage; and receiving the output from the voltage sudden change detection means to detect the sudden change in battery voltage when the battery voltage suddenly changes. An engine idle speed control device comprising: energization correction stop means for preventing correction of the energization mode based on voltage.