JPH01117964A - Intake air quantity controller for internal combustion engine - Google Patents

Abstract

PURPOSE:To secure the power generation quantity and improve fuel consumption by detecting the electric current value supplied into an electric load from an ac generator driven by an internal combustion engine and setting the aimed idle revolution speed of the internal combustion engine according to the result of the detection. CONSTITUTION:An internal combustion engine 1 drives an ac generator 21, which supplies electric power into an electric load 18. A control valve 6 controls the air quantity supplied into the engine 1 in idling operation. An ECU 9 receives the signals of a variety of sensors 11-16 for detecting the operation state of the engine 1 and the switches 24-27, and sets the control quantity of the control valve 6 on the basis of the difference between the aimed value and the actual value of the engine revolution speed in idling. In this case, the electric current value supplied into the electric load 18 is detected by a means 19. The aimed idle revolution speed is set by the ECU 9 according to the signal detected by the means 19.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an intake air amount control device for an internal combustion engine.
In particular, the present invention relates to an intake air amount control device for an internal combustion engine that aims to ensure the required power generation capacity of an alternator when the engine is idling and to improve the fuel efficiency of the engine.

(Prior art and its problems) As an intake air amount control device for an internal combustion engine, for example, as shown in Japanese Unexamined Patent Publication Nos. 56-116110 and 56-126634, a target idle rotation speed is set and this target The difference between the idle speed and the actual engine speed is detected, and the amount of air taken into the engine is adjusted according to the size of the difference so that the difference becomes zero, and the engine speed is adjusted to the target idle speed. A control device that performs lp control to maintain a constant number is well known. Further, the internal combustion engine is generally coupled to rotate and drive an alternator that supplies power to an on-vehicle electrical load such as a headlight I. Therefore, when the engine is idling, the amount of power generated by the generator changes depending on the engine speed, but if the engine speed decreases and there is a shortage of nm or m, the power is transferred from the battery to the electrical load. is supplied.

However, the power consumption by electrical loads varies greatly depending on the time of day (for example, at night when headlights are used and during the day when they are not used), or depending on the season and pond, and when there is a fluctuation in power consumption, , or when controlling the engine speed by controlling the amount of intake air as described above based on a fixed target idle speed, the following two conflicting demands must be met: There is a demand from the alternator side to keep the rotation speed low, and a demand from the alternator side to keep the engine rotation speed high to avoid excessive battery consumption no matter how the electrical load operates. It is not possible to respond to both at the same time.

The power generation characteristics of an alternator are: q? i! However, in this case, if the current consumption of the vehicle as a whole is small, the necessary power can be supplied to the electric load and the battery charge/discharge balance can be maintained, so no problem occurs. On the other hand, if the current consumption increases and the target idle speed of the engine is set low, the amount of power generated by the alternator driven by the engine will be insufficient, and the current will be supplied from the battery. If the amount increases and this state continues for a long time, there is a risk that the battery will run out. However, from this point on,
If the target idle speed is set high, more fuel will be consumed than necessary when current consumption is low, resulting in a problem of poor fuel efficiency.

(Object of the Invention) The present invention focuses on the above-mentioned points, and provides an internal combustion engine that can secure the necessary amount of power generation even with wide fluctuations in the amount of current consumption, and that can also improve fuel efficiency. The purpose of the present invention is to provide an intake air amount control device.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides an alternator driven by an internal combustion engine, an electric load supplied with electric power from the alternator, and an idle power supply to the engine. An intake air intake for an internal combustion engine, comprising a control valve that controls an intake air amount during operation, and a control amount setting means that sets a control claw of the control valve according to a target idle speed and an actual engine speed during idle. The air amount control device includes a detection means for detecting a current value supplied to the electric load, and a target idle rotation speed setting means for setting a target idle rotation speed according to the output of the detection means. This is how it was done.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings.6 Fig. 1 is a block diagram schematically showing the entire intake air amount control device for an internal combustion engine according to an embodiment of the present invention. For example, the symbol l indicates a four-cylinder internal combustion engine, and the engine 1 has an intake pipe 3 and an exhaust pipe 4 with an air cleaner 2 attached to the open end.
is connected.

A throttle valve 5 is arranged in the middle of the intake pipe 3, and an air passage 8 that opens into the intake pipe 3 downstream of the throttle valve 5 and communicates with the atmosphere is arranged. Atmospheric side I of air passage 8
An air cleaner 7 is attached to the end of the air passage 8.
An auxiliary air amount control valve (hereinafter simply referred to as "control valve") 6 is disposed in the middle. This control valve 6 is a normally closed solenoid valve, and is composed of a solenoid 6a and a valve 6b that opens an air passage 8 when the solenoid 6a is energized. connected.

A fuel injection valve 10 is provided between the engine l of the intake pipe 3 and the opening 8a of the air passage 8, and this fuel injection valve 10 is connected to a fuel pump (not shown) and electrically connected to the ECU 9. It is connected.

The throttle valve 5 has a throttle valve opening (θTl1).
A sensor 11 detects an opening 8a of the air passage 8 of the intake pipe 3.
An intake pipe absolute pressure (PB^) sensor 13 communicating with the intake pipe 3 via a pipe 12 is attached to the downstream side, and an intake Ft('r^) sensor 14 is attached to the downstream side thereof. An engine coolant temperature (Tw) sensor 15 and an engine rotation angle position (Ne) sensor 16 are respectively attached to the engine 1 body, and each sensor is electrically connected to the ECU 9.

The codes 171 to 17m are, for example, headlights, near conditioner (air conditioner) heater fans, and ? Electrical devices consisting of a magnetic clutch rake lamp, an electric radiator fan, etc. are shown, respectively. These electrical devices 171-17
m constitutes an electric load 18 that is supplied with power from an alternator, which will be described later, and a battery if necessary.

Each electrical device 171-17m has an individual switch for operating or controlling the energization (for example, a switch that opens and closes manually in the case of headlights, and a switch that changes the water temperature in the case of an electric radiator fan). (such as a switch for automatic activation in response), and are connected to the connection point 20a via a common power supply path, and further via a detection means I9 for detecting the current value supplied to the electrical load 18. has been done.

Between the connection point 20a and the ground, there is a voltage regulator that supplies field winding current to the field winding 21a of the generator 21 according to the load of the battery 20, the alternator 21, and the electrical devices 17+ to 17m. 22 are connected in parallel.

The detection means 19 may be configured using a Hall element, for example. In other words, by detecting the magnetic flux density due to the current flowing in a common power supply path using a Hall element, the
The electric load current value flowing from the electric load 18 from the electric load 11 and the battery 20 is detected, and this is used as the input data of the current consumption of the on-vehicle electric load, that is, the current consumption of the entire vehicle.
Supply to CU9.

Field winding current output terminal 2 of voltage regulator 22
A current detector 23 is installed on the line between 2a and the field winding 21a.
is interposed. The detector 23 receives a signal indicating the power generation state of the generator 21, for example, the voltage regulator 22.
A signal having a voltage level corresponding to the magnitude of the field winding current supplied to the generator 21 from the ECU 9 is supplied to the ECU 9.

The generator 21 is mechanically connected to the output shaft (not shown) of the engine l and is driven by the engine l.

Then, when the energizing switch of each of the electrical devices 17z to 17m is closed (on), power is supplied from the generator 21 to each of the electrical devices 17z to 17m, and each of the electrical devices 17w to 17m is powered.
When the power required to operate 17m exceeds the power generation capacity of the generator 21, the insufficient power is supplemented from the battery 20.

O; 1. The ECU 9 switches the target idle speed as described later in accordance with the operating states of certain loads among the electrical loads 18, namely the brake lamp, the electric radiator fan, the air conditioner fan, and the electromagnetic clutch. For control purposes, a brake switch 24, a radiator fan switch 25, a heater fan switch 26, and a clutch switch 27 are electrically connected.

The ECU 9 includes an input circuit 9a having functions such as shaping input signal waveforms from the various sensors mentioned above, correcting voltage levels to predetermined levels, and converting analog signal values into digital IR values, and a central processing unit. Circuit (hereinafter referred to as rCPUJ)
9b, storage means 9c for storing various calculation programs and calculation results executed by the CPU 9b, and an output circuit 9d for supplying drive signals to the fuel injection valve IO and the control valve 6.
Consists of etc.

The engine operation status parameter signals from the throttle valve opening sensor 11, absolute pressure sensor 13, intake temperature sensor 14, cooling water temperature sensor 15, and engine rotation angle position sensor 16, and the electric load current from the Hall element of the detection means 19 are detected. Indicating signal (current consumption measurement signal), switches 24 to 27
A detection signal representing the electrical load state from the detector 23
The power generation status signal is supplied to the CPU 9b via the input circuit 9a of the ECU 9, and the CPU 9b receives these engine operating status parameter signal values, electrical load current measurement signal values,
The engine operating state and the engine load state such as electrical load are determined based on the electrical load state signal value and the power generation state signal value, and the target idle rotation speed during idling operation is set according to these determined states, and the engine The amount of fuel supplied to l, that is, the opening time of the fuel injection valve 10 'I' OU
T and the amount of auxiliary air, that is, the control output value to the solenoid 6a of the control valve 6, for example, the solenoid 6a is a linear solenoid that controls the amount of intake air by changing the degree of opening of the valve 6b according to the amount of current. In the case of control, the solenoid drive current 1out to the solenoid is calculated, and a drive signal for operating the fuel injection valve 10 and the control valve 6 is supplied to each of them via the output circuit 9d in accordance with each calculated value.

Here, the solenoid drive current value is set according to the actual engine speed and the target idle speed, that is, according to the difference ΔN between the two.

The solenoid 6a of the control valve 6 is energized according to the solenoid drive current calculated in 1); the valve 6b is opened to an opening degree corresponding to the drive current to open the air passage 8 and the opening degree is A required amount of auxiliary air according to the amount of air is supplied to the engine l via the air passage 8 and the intake pipe 3.

The fuel injection valve 10 is opened for an opening time corresponding to the calculated value, and injects fuel into the intake pipe 3. The injected fuel is mixed with intake air, and a mixture with a desired air-fuel ratio is injected into the engine. It is designed to be supplied to l.

When the amount of auxiliary air is increased by increasing the opening degree of the control valve 6, the amount of air-fuel mixture supplied to the engine 1 increases, the engine output increases, and the engine speed increases. Conversely, if the opening degree of the control valve 6 is reduced, the amount of air-fuel mixture supplied decreases and the engine speed decreases. In this manner, by controlling the amount of auxiliary air, that is, the opening degree of the control valve 6, the engine speed during idling is controlled.

That is, the target idle speed is set as described above, the difference between this target idle speed and the actual engine speed is detected, and assistance is applied to the engine 1 according to the size of the difference so that this difference becomes zero. Feedback control is performed to supply air and maintain the engine speed at the idling speed.

FIG. 2 shows the above-mentioned [1 standard idle This is a flowchart of a control program for switching and setting the rotation speed according to the amount of current consumption, in which (a) shows a subroutine for obtaining a signal value representing the electrical load current to be determined, and (b) ) indicates the target idle rotation speed calculation subroutine. This program executes the Ne sensor 1 in the CPU 9b of the ECU 9.
A predetermined crank angle position signal from 6 (hereinafter referred to as r'r)
It is executed every time a DC signal (referred to as a "DC signal") is input.

First, in step 201 of FIG. 10A, it is determined whether the brake is on or not, and if the answer is affirmative (Yes), the electric load current obtained from the Hall element of the detection means 19 is displayed. A predetermined value ELa is subtracted from the signal value EL (specifically, the signal value after A/D conversion), that is, the current consumption value of the entire electrical load 18 (the electrical loads 11 and 2).Step 202) If the answer is negative (NO), step 202 is skipped.

Next, it is determined whether the radiator fan is on or not (step 203), and if the answer is 1 (Yes), a predetermined value ELg is further subtracted from the signal value EL (step 204), and the answer is negative ( If NO), then step 2
04 is also skipped.

The predetermined value ELB is a value preset according to the power consumption of a brake lamp, which is one of the electrical devices in the electrical load 18, and the predetermined value ELR is similarly one of the electrical devices. This value is preset according to the power consumption of the radiator fan, and in steps 202 and 204 above, when the brake is on and when the radiator fan is on,
These values ELe.

By subtracting ELR from the signal value EL based on the detection output of the Hall element in advance, the first discrimination value E1,1, which will be described later, is obtained.
And, the electric loads for the brake and the radiator fan are excluded from the signal value EL for the to-be-determined signal to be compared and determined with the second determination 4f11EL2 (FIG. 2(b)).

This is due to the following reasons.

In a vehicle, brake lights and electric radiator fans are quite large electrical loads, and they
It usually belongs to the type of electrical equipment that is used all the time, day and night. On the other hand, as will be described in detail later, this embodiment measures the current consumption n1 using a Hall element, selectively sets the target idle rotation speed to different values depending on the magnitude of the current consumption, and controls the engine 1. Control is performed to change the idle rotation speed, but in such control, if the target idle rotation speed is set to change including the current consumption by the above-mentioned types of electrical devices, the power supply to the electric device, The idle speed will fluctuate each time the engine is shut off. For example, as mentioned above, the brake lamp is a large electrical load, so each time the brake pedal is operated, the electrical load current increases or decreases, and as a result of this, the idle speed is switched, and the idle control The idle speed changes up and down by controlling the amount of intake air by the control valve 6 as the controller fiv (EACV).

In addition, in normal operation of Il1 cars, the brakes are turned on and off, and the radiator fan is turned on and off frequently (in the case of a radiator fan, the water temperature sensor detects when the water temperature reaches, for example, 85 to 90 degrees Celsius). Since the engine is also an automatic engine (operating automatically), the above-mentioned fluctuations in the idle speed will occur frequently, and such up and down fluctuations in the idle speed are not desirable in terms of product quality.

Therefore, we created a program for the EL to be determined as shown in Figure 2(a), and turned on the brake and radiator fan.
Based on the detection output of switches 24 and 25 for off detection,
A predetermined 11IIELn corresponding to these current consumption values,
The ELR is subtracted from the signal value EL corresponding to the amount of current in the entire vehicle detected by the detection means 19 (steps 202 and 204), so that a target value is determined for a change in a specific load among the electrical loads 18. Changes in idle speed are suppressed.

The target idle rotation speed calculation subroutine shown in FIG. 2(b) is executed subsequent to the routine shown in FIG. 2(a).

First, in step 205, it is determined whether or not the air conditioner fan is on. If the answer is affirmative (Yes), the process proceeds to step 206 and subsequent steps; if the answer is negative (No), the process proceeds to step 212. move on.

In this program example, such a determination is made by setting the set value of the target idle rotation speed in the engine warm-up state to the lowest first predetermined rotation speed NOB (described later) and a second predetermined rotation speed higher than that. Step 218.
222.210), and accordingly, a first discrimination value E1,1 and a second discrimination value larger than this (1αEL2) are set as discrimination values for determining the magnitude of the signal value EL. However, when the heater fan is on, the current consumption may increase due to the operation of the air conditioner. Therefore, in such a case, first, the comparison with the second discriminant value EL2, which has a larger value, is performed. This is to cause necessary processing following the determination to be performed.

That is, in step 206, the signal value EL obtained through the Hall element of the detection means 19, or the predetermined value ELB and/or when the brake and/or radiator fan is on, is determined.
Alternatively, it is determined whether the signal value EL obtained by subtracting EL and R is larger than a second discrimination value (for example, 22A), and the answer is affirmative (Yes), that is, EL>EL2 is established and the signal is erased. *If the current is large, it is determined whether the electromagnetic clutch for connecting the air conditioner is on (step 207). When the answer to step 207 is affirmative (Yes), the third
The count value of the Ttt2oLy timer (step 223) is reset to 0 (step 208), and if the answer is negative (NO), step 208 is skipped, and the count value of the third 'rEL2oty timer is reset. is O (step ZOO), and if the answer to step 209 is affirmative (Yes), [one standard idle rotation speed N0BJ is changed to a third predetermined rotation speed N0BJ11
(e.g. 750 rpm) step 210)
, proceed to step 224, which will be described later.

As a result, when the current consumption is large, the third predetermined rotation speed N0BJI with the highest target idle rotation speed N0IIJ is set.
+, and the idle speed of the engine l is controlled to increase toward this target value.

As mentioned above, the determination regarding the clutch and the third 1°ε
The reason for providing steps 207 and 208 for forcibly resetting the L2DLY timer is that when the air conditioner is running and the electromagnetic clutch is on, the electromagnetic clutch consumes a large amount of power. In this case, in order to promptly increase the power generation capacity of the alternator 21 driven by the output of the engine 1, the target idle speed N is immediately increased.
0BJ is the highest third predetermined rotation speed N0IIJI+
This is because it is necessary to switch to

On the other hand, even when E L ) r bow L 2, if the clutch is not on, unlike the above, step 20
If 8 is skipped and the result is overcast, step 2
In step 09, it is determined whether a predetermined time T+:t2nty has elapsed by the third ゛1゛εL2DLY timer in fji. If it is within the predetermined time, the previous value N0BJ is maintained (step 2+1). , when the predetermined time 1'EL2DLY has elapsed, the target idle rotation speed N0BJ is switched to the third predetermined rotation speed N0IIJ11 (step 210). As stated in ``YU'', the target idle rotation speed N0RJ is changed for a predetermined period of 1゛εL2.
The purpose of prohibiting DLY is to prevent the target idle speed N0BJ from being switched due to instantaneous or relatively short-term fluctuations in load current, current value fluctuations, etc., and to prevent frequent rotation. This is to avoid fluctuations in numbers.゛If the answer to step 206 is negative (NO), the current consumption is not so large, so 1] the target idle rotation speed N0
BJ is set to the third predetermined rotation speed NOBJI is set to the lower second
Step 222), set the predetermined rotational speed NOIIJM (for example, 650 rpm) to the third rotation speed NOIIJM (for example, 650 rpm).
The 2DLY timer is reset and started (step 223), and the process proceeds to step 224, which will be described later.

0; When the heater fan i is off, that is, when the determination result of the determination step 205 is negative (NO), it is determined whether the intake air temperature T^ is higher than the predetermined temperature TANOBJ (for example, 15° C.). If the answer is affirmative (Yes), that is, 'FA>"1" ANOBJ is established and there is no low intake temperature state, the above-mentioned signal value EL is determined.
is larger than the first discrimination value EL1 (for example, 9A) which is smaller than fl E L 2 (step 213), and if the answer to step 213 is negative (No), then Proceed to step 214. If the answer to step 212 is negative (N, o), that is, if the intake air temperature T^ is a low intake air temperature below the predetermined temperature TANOIIJ, then the signal value EL is greater than the second determination value E1, 2. The process advances to step 215 in which it is determined. When the intake temperature is low (for example, when operating in a cold region), if the idle speed of the engine is lowered too much, it will be difficult to maintain good combustion conditions. , 2 of the predetermined rotation speed N0IIJ11 of the fj42 and the third predetermined rotation speed N0BJI+
This is because it is controlled using one.

Further, when the answer to step 213 is affirmative (Yes), that is, EL>EI, +, the process similarly proceeds to step 215 for determining the signal value EL.

When proceeding from step 213 to step 2!4,
That is, when the intake temperature T^ is high and the current consumption is low, it is determined again whether the brake is on or not, and if the answer is negative (No), the predetermined time tot, yB (for example, 35 Reset and start the first t DLYB timer that measures 11 seconds) (step 216).
, furthermore, the above-mentioned 3rd c7) 'r EL2DLY
Similar to the timer, the predetermined time 'I'' is used to provide a certain amount of grace when changing the set value of the target idle rotation speed N0BJ.
The second 'measures the ELIDLY (e.g. 3.5 seconds)
The rELIDLY timer is reset and started (step 217), and the target idle speed NO[
lJ to a first predetermined rotation speed N011JL (for example, 600!・I) I which is lower than the second predetermined rotation speed NO8JM.
Step 218), step 2)
Proceed to 23 onwards.

As a result, when the current consumption is low, the target idle rotation speed N0BJ is set low, making it possible to reduce the idle rotation speed.

When a determination result of 19 constant (Yes) is obtained in step 214, that is, when the brake is on, it is determined whether or not the on state continued for the predetermined time tDLY11 determined by the first tDLY11 timer. It is determined (step 219). Even if the brake is turned on, if it does not continue for the predetermined time tDLY11 (step 219
If the answer is negative (NO), step 217
．． Step 218 is executed and the set value of the target idle rotation speed NOBJ is maintained at the first predetermined rotation speed NO3, but if the brake is kept on for a predetermined time t DLYB, the answer to step 219 is 1i constant (Yes). So step 2
20 or less are executed.

In this case, the previous target idle rotation speed N0BJ is not the third predetermined rotation speed N0BJI+ (therefore, step 2
20 is negative (No), and the second position III
Since the LY timer has timed up (therefore, the answer to step 221 is 1q constant (Yes)), the target idle rotation speed N0BJ is changed to the second predetermined rotation speed N0IIJ11 (step 222).

This is based on consideration of the following points.

As mentioned above, in this program example, the program shown in FIG.
) In step 202, when the brake is on, processing is performed so that the current consumption is not reflected in the signal value EL for discrimination. This focuses on variations in rotational speed when the driver operates the brake pedal in a normal manner, but depending on the situation, there may be cases where the driver continues to press the brake pedal for a long time. in this case,
Although the amount of power consumed by the brake lamp is large, this amount is subtracted from the signal value E[, and this has a large effect on the charge/discharge balance of the battery 20. That is, although current consumption increases due to keeping the brake pedal pressed for a long time, this variation is not included in the EL value used in each determination step 206, 213, and 215, and therefore, as it is, the target idle rotation number no
[The setting value of lJ is not changed. For this reason, even though the amount of electric power taken out from the battery 20 increases, the power generation capacity of the alternator 21 remains the same, and the charge/discharge balance is disrupted, so it is necessary to correct this.

Therefore, when the brake pedal is depressed for a long time exceeding the predetermined time tDLYB, the set value is unconditionally switched from the first predetermined rotation speed NOB to the second predetermined rotation speed NOIIJM, which is higher than this ( Step 220
~222), thereby increasing the rotational speed of the engine 1 and, therefore, the rotational speed of the alternator 21.

Fluctuations in power consumption during electrical load 18 (excluding those caused by brakes and radiator fans)
Is El > 1′? , l, 1 holds true and the process proceeds to step 215, the signal value El, becomes the !th!
If the target idle rotation speed N0BJ exceeds the second discrimination value EL+ but falls within the second discrimination value EL2, it is determined whether the previous target idle rotation speed N0BJ was set to the third predetermined rotation speed N0BJI+ (step 220); The answer is negative (NO)
In this case, it is determined whether or not a predetermined time period of 1'εLI DLY by the second TεLIDLY timer has elapsed (step 221), and the answer to step 221 is negative (No).
), that is, before the predetermined time has elapsed, step 21
8 is executed. Therefore, if the previous set value is the first predetermined rotation speed NO3, that state continues.

As a result, if the energization to the load that caused the above-mentioned fluctuation in current consumption is cut off within the predetermined period of time, the first predetermined rotation speed NO3 is maintained as the target idle rotation speed N0BJ. . On the other hand, EL (EL
If the state of +≦EL2 continues beyond the predetermined device IDLY, that is, if the answer to step 221 is 1 constant (Yes), the second set value is changed at that point in response to the increase in the electrical load current. Switching to the predetermined rotation speed NOBJM is performed (step 222).

The reason why the predetermined time period 1゛εLIDLY has to pass as a condition for changing the set value is the same as that explained in step 209 above.

When the answer to step 220 is Yes, step 221 is skipped and the process proceeds to step 222. That is, in this case, the previous setting value is the third predetermined rotation speed N.
0BJI+, and the setting value is changed from the corresponding N0IIJ11 to the second
When lowering the set value to the predetermined rotation speed NOBJM, it is better in terms of fuel efficiency to lower the set value immediately without waiting for the determination in step 221, so in such a case, the above-mentioned skip can be applied. There is.

Further, if the answer to step 215 is affirmative (Yes), that is, the signal value El exceeds the second predetermined value E L 2, steps 209 and subsequent steps are executed, and the previous time is set as the target idle rotation speed. Value or third predetermined rotation speed N0B
J11 is set (steps 210, 211).

In any of steps 210, 211, 218, and 222 described above, the target idle rotation speed N0B during the current loop is determined.
After J is set, the process proceeds to step 224, where it is determined whether the engine cooling water temperature 'rw is higher than a predetermined temperature TwN2 for determining whether the engine 1 is in a warm-up completion state. However, if the answer is affirmative (Yes), that is, after warm-up, this program is immediately terminated.

Therefore, in this case, la set in any of the above steps 210, 211, 218 and 222 is applied as the target idle speed N0BJ, and the engine is controlled by the intake air type control by the control valve 6 based on the target value. 1 idle speed is controlled.

As described above, when the engine is warmed up, the detection means 1
The current consumption value of the entire vehicle (in this example, the brake and electric radiator fan are excluded) is constantly monitored through the Hall element No. 9, and the target idle rotation speed NO [lJ is changed according to the current consumption amount. By doing so, the idle speed can be lowered when the current consumption is low, and the idle speed can be increased when the current consumption is large. Since the number can be reduced, fuel efficiency can be improved.

If the answer to step 224 is negative (No), that is, if the engine l is cold and in the process of being warmed up, a first idle target rotation speed determined according to the engine coolant temperature Tw is set in the storage means 9c of the ECU 9. This table is read out from the table and compared with the set value set according to the above-mentioned amount of current consumption. That is, it is determined whether or not the set target idle rotation speed N0BJ is greater than or equal to the table-calculated target rotation speed N0IIJ (step 225). If the answer is 1 (Yes), this program is terminated, and the answer is negative (No). When , target idle speed N0BJ
This program is then replaced with the latter table calculated target rotation speed N0IIJ. Therefore, in the state until the engine l completes warming up, whichever of the set values at each of the predetermined steps 210, etc. and the calculated value from the table is larger is the target idle rotation speed N.
Selectively adopted as 0IIJ. As a result, warm-up can be promoted until warm-up, and under certain conditions, that is, when the set value in each predetermined step 210 etc. is selected as being larger, furthermore, as described above, Control that also takes into account idle rotation speed control corresponding to the amount of current consumption will be executed.

In the above embodiment, the target idle speed N0IIJ is changed in three stages according to the signal value EL, but the target idle speed N0BJ is changed linearly according to the signal value EL. It may be changed. In addition, regarding the suppression of changes in the target idle rotation speed N0RJ, switching is prohibited for a predetermined period after a change in electrical load current is detected, but this is not limited to this.
It is also possible to change the mode so that the amount of change in the number of rotations is reduced or the number of rotations is gradually changed.

Furthermore, in the above embodiment, the amount of auxiliary air is controlled by varying the magnitude of the drive current to the solenoid 6a of the control valve 6. However, the present invention is not limited to this. Duty ratio control may also be performed.

(Effect of the invention) .

According to the invention, an alternating current l driven by an internal combustion engine
vl! an electrical machine, an electric load supplied with power from the alternator, a control valve that controls the intake air amount to the engine during idling operation, and a control valve 11m that controls the control valve 11m to the target idling speed and the actual idling speed. In the intake air amount control device for an internal combustion engine, the intake air amount control device for an internal combustion engine includes a control amount setting means for setting a control amount according to the engine rotational speed; Since the engine is equipped with a target idle speed setting means for setting the target idle speed, the engine speed can be changed according to the current consumption caused by the electrical load, and when the current consumption is large, the engine speed can be increased. By increasing the number of revolutions when the number of revolutions is low, it is possible to improve fuel efficiency while satisfying the demand for charge/discharge balance of the battery.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the overall configuration of an intake air amount control device for an internal combustion engine according to an embodiment of the present invention, and FIGS. 2(a) and (b) are examples of subroutines for determining the EL value to be determined. and a flowchart illustrating an example of a subroutine for calculating the target idle rotation speed N0BJ. 1... Internal combustion engine, 6... Auxiliary air control valve, 7.
・・Electronic control unit (ECU), 17+~1
7m...Electrical equipment, 18...Electrical load, 19...
Detection means, 21... alternator.

Claims (1)

[Scope of Claims] 1. An alternator driven by an internal combustion engine, an electrical load supplied with electric power from the alternator, and a control valve that controls the amount of intake air to the engine during idling operation;
An intake air amount control device for an internal combustion engine, comprising a control amount setting means for setting a control amount of the control valve according to a target idle speed and an actual engine speed at idle,
An internal combustion engine characterized by comprising a detection means for detecting a current value supplied to the electric load, and a target idle rotation speed setting means for setting the target idle rotation speed according to the output of the detection means. Intake air amount control device. 2. Claim 1, further comprising prohibition means for prohibiting the target idle rotation speed setting means from changing the target idle rotation speed for a predetermined period after the output of the detection means changes. An intake air amount control device for an internal combustion engine as described in . 3. Claim 1, further comprising a suppressing means for suppressing a change in the target idle rotation speed by the target idle rotation speed setting means with respect to a change in a specific load among the electrical loads. Intake air amount control device for internal combustion engines.