JPS6022038A - Feedback control method for idling speed of internal- combustion engine - Google Patents

Abstract

PURPOSE:To prevent abrupt drop of the engine speed at the time when electric means such as head lamps, a rediator fan, etc. are turned form ON to OFF, by detecting change in the quantity of operation of an intake control valve, and keeping the quantity of operation just before ON/OFF switching of the electric means in case that the detected change in the quantity of operation of the intake control valve is smaller than a prescribed value. CONSTITUTION:A valve 6 for controlling the flow rate of auxiliary air is disposed at a portion of an air passage 8 that is communicated with the atmosphere and connected to an intake passage 3 on the downstream side of a throttle valve 5, and the idling speed of an engine is controlled by controlling the valve 6 by an ECU9. In such an apparatus, the quantity of operation of the control valve 6 is corrected by the ECU9 according to the correction value obtained from the ON/OFF conditions of electric means 16-18 such as head lamps, a radiator fan, a heater fan, etc. Further, when the electric means 16-18 are turned from ON to OFF, change of the above correction value is detected. In case that the degree of change in the above correction value is smaller than a prescribed value, the quantity of operation of the control valve 6 is controlled to keep a value just before causing ON/OFF switching of the electric means, whereby it is enabled to prevent abrupt drop of the engine speed.

Description

[Detailed description of the invention]

The present invention relates to an idle rotation speed feedback control method for an internal combustion engine, and in particular to an idle rotation speed control method that suppresses changes in the engine rotation speed when the electrical load on the engine decreases during feedback control, and improves the control f511 Wj degree. Concerning several foot bag control method. Conventionally, a target idle speed is set according to the engine load condition, the difference between this target idle speed and the actual engine speed is detected, and the size of the difference is calculated so that this difference becomes a cloud. An idle speed feedback control method has been used in which the amount of air taken into the engine is adjusted according to the engine speed to maintain the engine speed at a target idle speed. No., Japanese Patent Publication No. 5
No. 6-126634). In such a method, when an electric device such as a headlight is operated, a generator that supplies power to the electric device is operated, and this operation places a load on the engine, causing a reduction in engine speed. In order to solve this problem, the applicant has developed an idle speed feedback control method that increases or decreases the amount of air taken into the engine in response to the on/off state of the electrical device before the effect of increased load appears on the engine speed. (Japanese Patent Application No. 57-066928). However, if the power required by the electrical equipment exceeds the generating capacity of the generator, the insufficient power is supplemented by the battery, so the on/off state of the electrical equipment may not correspond to the engine load state. arise. That is, for example, in FIG. 1, power is supplied from the battery to the electrical device, and the battery voltage Vo becomes a predetermined voltage V B E a
When the following consumption conditions occur (Sn in Figure 1 (b)), the generator charges the battery even after the electrical equipment is turned off, so the full power generation state is maintained and the engine continues to run even when the electrical equipment is turned off. will still be burdened by the operation of the generator. Therefore, if the amount of intake air is immediately reduced (Sn' in FIG. 1(c)) when the electrical device is turned off (Sn in FIG. 1(a)). The amount of air commensurate with the load is not supplied to the engine, and as a result, the engine speed suddenly decreases, and then is gradually returned to the predetermined engine speed by feedback control (the broken line in Figure 1 (d) ). This decrease in engine speed not only causes discomfort to the driver, but also delays battery charging, and the sudden decrease in engine speed II! If the flange is engaged with i, there is a risk of an entrenched stall. The present invention has been made in view of the above-mentioned points. Therefore, the operating amount of a control valve for adjusting the amount of intake air of an internal combustion engine including a plurality of electrical devices and a power supply circuit for supplying electric power to these devices is set to idle. The idle speed feedback control method performs control according to the difference between the actual engine speed and the target engine speed at the time, the on-off state of each of the electrical devices is detected, and the on-off state is based on the detected on-off state. A correction amount for correcting the operating amount is determined and the operating amount is corrected, and when the at least one electrical device changes from on to off, an amount of change in the correction amount is determined, and the amount of change is a predetermined value. When it is smaller, it maintains the operating amount before the change of the on-off state of the electrical device and ensures that the engine speed decreases when the electrical device changes from the on state to the off state regardless of the battery consumption state. It is an object of the present invention to provide an idle speed feedback control method for an internal combustion engine that prevents the above. An embodiment of the method of the present invention will be described below with reference to the drawings. FIG. 2 is a diagram schematically showing the entire engine speed control device for an internal combustion engine to which the method of the present invention is applied, and reference numeral I indicates, for example, a four-cylinder internal combustion engine;
An intake passage (hereinafter referred to as "intake pipe") 3 having an air cleaner 2 attached to the open end thereof is connected to an exhaust pipe 4. A throttle valve 5 is arranged in the middle of the intake pipe 3, and an air passage 8 is arranged which opens into the intake pipe 3 on the downstream side of the throttle 4t5 and communicates with the atmosphere. An air cleaner 7 is installed at the open end of the air passage 8 on the popular side, and an auxiliary air amount control valve (hereinafter simply referred to as [control valve j
6) are arranged. The control valve 6 is a normally closed solenoid valve, and is composed of a solenoid 1<6a and a valve 6b that opens the air passage 8 when the solenoid 6a is energized. Below r
It is electrically connected to E CU J) 9. A fuel injection valve IO 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 is electrically connected to the ECU 9. It is connected to 1+. A throttle valve opening sensor 1 is installed in the Scots 1 to 5.
1 is the opening of the air passage 8 of the intake pipe 3. On the downstream side of the intake pipe 18a, there is an intake pipe absolute pressure sensor 13 that communicates with the intake pipe 3 via a pipe 12, and on the engine 1 body, an engine cooling water temperature sensor 14 and an engine The rotation angular position sensors 15 are respectively mounted, and each sensor is electrically connected to the ECU 9. Reference numerals 16, 17 and 18 indicate the first, second and third parts of the headlight 1-, brake lamp, radiator fan, etc.
Showing electrical devices, first, second and third electrical devices 16.1
7.18 are switches 16a and 17a, respectively. +8a and the battery ]9 via the connection point 19a, and are also directly connected to the ECU 9, respectively. An alternating current generator 20 is connected to the connection point t9a, and a regulator 20a is connected in parallel to the generator 20. The regulator 20a controls the field current of the generator 20 according to the output voltage value of the battery I9. is configured to do so. The generator 2o is mechanically connected to the output shaft (not shown) of the engine 1 and is driven by the engine 1. Then, each switch] (iQ, 17a, 18a is closed (on), and each electrical device 16, 17, 18
Electric power is supplied from the generator 20 to each electrical device 16.1.
7.18 exceeds the power generation capacity of the generator 20, the regulator 20a operates and sets the field '6J & current to the maximum rated current to generate power Ia20.
to full power generation. However, the still insufficient power is supplemented from the battery 19, and due to this supplementary power from the battery 19, the battery j9 is exhausted and the battery 19 is
The output voltage value Vo decreases from a predetermined value V[lCG. Therefore, when the battery 19 is in a depleted state, the switches 16a, 17a are activated. ], even if some or all of 8a are in the open (off) state, the load of the generator 20 continues to be applied to the engine 1 because it is in a full power generation state until the battery power is restored. Respective engine operating state parameter signals from the throttle valve opening sensor 11, absolute pressure sensor 13, cooling water temperature sensor 14, and engine rotational angle position sensor 15 are supplied to the ECυ9, and the ECU9 in turn receives the values of the engine operating state parameter signals. and first, second and third electrical devices 16.17.
The engine operating state and engine 11 load state are determined based on the electrical load state signal from 18, and the fuel supply amount of the engine 11\, that is, the opening of the fuel injection valve 10, is determined depending on the time and auxiliary air according to these determined states. The amount, that is, the operating claw of the control valve 6, and in this embodiment the valve opening time of the control valve 6, are calculated respectively, and the fuel injection valve 10 and the control valve 6 are adjusted according to each calculated value.
A driving pulse signal is supplied to each of them. The solenoid 6a of the control valve 6 is energized for a valve opening time corresponding to the calculated value, opens the valve 6b, and opens the air passage 8, so that a predetermined amount of air according to the valve opening time flows into the air passage and the intake pipe. 3 to the engine 1. The fuel injection valve 10 is opened for a valve opening time according to the above-mentioned calculated value to inject fuel into the intake pipe 3, and the injected fuel is mixed with the intake air and always maintains a predetermined air-fuel ratio (for example, stoichiometric air-fuel ratio). The air-fuel mixture is supplied to the engine 1. When the amount of auxiliary air is increased by lengthening the opening time of the control valve 6, the amount of air-fuel mixture supplied to the engine I increases, the engine output increases, and the engine speed increases. Conversely, if the opening time of the control valve 6 is shortened, the amount of air-fuel mixture to be supplied will decrease and the engine speed will decrease. By controlling the supply of auxiliary air, that is, the opening time of the control valve 6, the engine speed can be controlled. FIG. 3 is a diagram showing the circuit configuration inside the ECU 9 of FIG. 2, in which the output signal from the engine rotation angle position sensor 15 of FIG.
Central processing unit (hereinafter referred to as rcPUJ) 9 as a signal
02 and is also supplied to the Me counter 903. ``Mt=The counter 903 counts the 114° interval from the input of the previous TDC signal from the engine rotation angle position sensor 15 to the input of the current TDC signal as H1, and the counted value Me is the engine rotation speed. It is proportional to the reciprocal of Ne.The Me counter 903 supplies this numerical value Me to the CPU 902 via the data lot 904.The throttle valve opening sensor TL, the intake pipe absolute pressure sensor 13, and the water temperature sensor shown in FIG. Detection signals from various sensors such as
The signal is supplied to a D converter 907. A/D converter 9
07 sequentially converts the detection signals from the aforementioned sensors 11, 13, 1.4 into digital signals and supplies the digital signals to the CPU 902 via the data bus 904. The first, second and third electrical devices 16° 17. shown in FIG.
18 respective switches 16. The on-off signals from a, 17 a, and 18 a are corrected to a predetermined voltage level in a level correction circuit 908, and then converted to a predetermined signal in a data input circuit 909 and supplied to the CP'U 902 via a data bus 904. . The CPU 902 further connects a read-only memory (hereinafter referred to as ROMJ) 9]0, a random access memory (RAM) 911, and a drive circuit 9 via a data bus 904.
], 2,913, and RAM911 is connected to CP
Temporarily stores calculation results etc. in U902 and stores them in ROM91.
0 stores control programs and the like executed by the CPU 902. The CPU 902 is a control programmer stored in the ROM 910! , the valve opening duty ratio D of the control valve 6 that determines the engine operating state and engine load state according to the aforementioned various engine parameter signals and controls the amount of auxiliary air.
o Calculate U T and control 13 corresponding to this calculated value
The signal is supplied to the drive circuit 912. The valve opening duty ratio DoUT of the control valve 6 is calculated based on, for example, the following equation (1). Do u T=Dp ln+Dt n--(1) Here, DpIn is a value (hereinafter referred to as feedback mode term) calculated according to the difference between the initial engine rotation speed and the actual engine rotation speed, as described later. DEn is a value calculated based on the on-off state of the electrical device I6.17.18, that is, the electrical load (hereinafter referred to as electrical load term), as will be described later. The CPU 902 further determines the fuel injection time T of the fuel injection valve JO.
oUT is calculated, and a control signal based on this calculated value is supplied to the drive circuit 913 via the data bus 904. The drive circuit 913 supplies the fuel injection valve 10 with a control signal to open the fuel injection valve 10 according to the calculated value, and the drive circuit 912
supplies the control valve 6 with an on-off drive signal that turns the control valve 6 on and off. FIG. 4 is a flowchart showing a method of calculating the electric load term Dcn, and this calculation block is TD in 1ΣCU9.
Executed every C signal. When the DEn calculation programmer 11 is called (step 1 in FIG. 4), first, the memory value of DEn is reset to zero (step 2).Next, the second electric device 1 shown in FIG.
It is determined whether or not the switch 16a of No. 6 is in the on state (step 3), and if the result of the determination is negative (NO), the process proceeds to step 5. In step 3, the discrimination result is determined to be 1 digit (vcS
), a predetermined value 1Dt1 corresponding to the electrical load of the first electrical device 1G is added to the stored value of Dcn, and this added value (D"n
+Dc1) as the new stored value of En (Step 4
). Note that since D E n =0 was reset in step 2, the new stored value of one ET+ in step 4 is equal to DE+. Next, the switch of the second electric device 17] 7a as described above
The on-off state of is determined (step 5), and if it is not on, the process advances to step 7, and if it is on, D E
A predetermined MD E 2 corresponding to the electrical load of the second electrical device 17 is added to the stored value of 11, and this added value (D I:n
10D E 2 ) as a new stored value of cn (Step 6). Further, as described above, the third electric device 1
The on/off state of the switch 18a of No. 8 is determined (step 7), and if it is not on, the process proceeds to step 9, which will be described later. If it is on, the stored value of D E n is set to the electrical load of the third electrical device 18. The corresponding predetermined amount DE3 is added, this added value (DEn+DE3) is set as a new value [step 8) as the stored value of n, and the process proceeds to step 9. In step 9, the stored value of DEn is set to a predetermined maximum value DEM.
It is determined whether or not it is larger than AX, and the determination result is negative (N
In the case of o), the execution of the current loop of the program is ended, and the stored value of Dan is applied as the electrical load term. If the determination result in step 9 is affirmative (YES), that is, DE
If the stored value of n is larger than the maximum value DEIIIAX, proceed to step IO, set the maximum value DEMAX as the new tα value of cn, end the execution of the current loop of the program, and set the maximum value DEMAX to the electric Apply as a load term. This value DEIIIAX is a value corresponding to the maximum load of the generator 20 applied to the engine, and if the field current of the generator 20 is the maximum rated current value, no greater load will be applied to the engine. It is preset to a value commensurate with the load. FIG. 5 shows the valve opening duty ratio DOUT of the control valve 6 using the electric load term D[n determined by the calculation program shown in FIG. 4 and the boot bank mode term D p In calculated by the method described later. This calculation program is also executed in the ECU 9 using the TDC signal. When this program is called (step 21 in FIG. 5(a)), first, a number Me proportional to the reciprocal of the actual engine speed Ne is changed to a number M corresponding to the reciprocal of the upper limit value N H of the target idle speed. It is determined whether or not it is smaller than H (step 22). If the result of this determination is negative (NO), (
That is, Ne≦NH). Proceeding to step 23, the number Me is a number M corresponding to the reciprocal of the lower limit value NL of the target engine rotation speed.

[Determine whether it is larger than When the determination result in step 23 is negative (No), that is, the determination result in steps 22 and 23 indicates that the engine rotation speed Ne is above the target engine rotation speed.
When it is determined that the actual engine speed Ne is between the lower limit values NH and NL, there is no need to increase or decrease the actual engine speed Ne, so the deviation value 1s M n is set to the atmosphere (step 24), and the value of the feedback type Dp+n is set to the previous value. Loop value Dp+n-1
(step 25), and step 2G (Fig. 5 (
Proceed to b)). Note that the above-mentioned values MH and ML are, for example, based on the cooling water temperature sensor 1.
The exhaust gas characteristics and fuel efficiency characteristics are set to be optimal according to the engine load such as the water temperature signal from 4 and the near conditioner. If the determination result in step 23 is affirmative (YES), it means that the actual engine speed Ne is determined to be smaller than the lower limit value N+, and in step 27, the deviation value ΔMn (in this case ΔMn is a positive value) is determined to be smaller than the lower limit value N+. The integral control term ΔD+ is calculated by multiplying this deviation value ΔMn by a constant number (+).
Step 28). Next, the difference between the deviation value ΔM n determined in step 27 and the deviation value ΔM n −4 in the previous loop, that is, the acceleration deviation value ΔΔMTl is determined (step 29), and this acceleration deviation value ΔΔMn is multiplied by a constant number Kp. Then, the proportional control term ΔL
) p is determined (step 30). The value obtained by adding the control value Dρ1n-2 of the previous loop to the integral control term ΔD1 and proportional control term Δ1]p determined in this way is used as the current feedback mode class D11.
+s+ (step 31), and then the process proceeds to step 26 (FIG. 5(b)), which will be described later. If the determination result in step 22 is the previous run (Yl!: S), it is determined that the actual engine speed Ne is greater than the upper limit value N-1 of the target idle number, and step 32
The deviation value ΔMn (in this case, ΔMn becomes a negative value) is determined at step 28, and the integral control term ΔD1.
In step 30, the current feedback modes 1 to Dp+n are determined using the proportional control term ΔDp and step 3, and the process proceeds to step 26. When the fee 1 to backmoat term D p' + n are set in step 25 or step 31, it is next determined whether the electrical load term DEn-1 at the previous loop was greater than zero, that is, the electrical load was (step 26), and if there was no electrical load at the previous time (if the determination result is negative (No)), the process proceeds to step 33, where the valve opening duty ratio of the control valve 6 is set to 1. ) o U T is set as the sum of the feedback motes Dp+n at this time and the electric load term DE11 at this time based on the above-mentioned equation (1). If the determination result in step 26 is affirmative (VES), that is, if an electrical load was applied to the engine last time,
Next, it is determined whether the current electrical load has decreased from the previous time. This is the difference Δ between the electrical load term between this time and the previous time.
DE n = Dr: It is determined whether n -DE n -( is smaller than atmosphere (step 3 lI), and if the determination result is negative (No), that is, if there is no change in the electrical load or at this time. If the electrical load has increased from the previous time, the process proceeds to step 33 in the same manner as described above, and the valve opening duty ratio DOIJT of the control valve 6 is determined by calculating the current fee 1<noh mode term D p In and the current electrical load term DEn. If the determination result in step 34 is affirmative (YES), that is, if the electrical load applied to the engine has decreased compared to the previous time, the change star ΔDI-n (ku0) of the electrical load term is set as a negative value. It is determined whether or not it is smaller than a predetermined amount ΔDa (step 35
). This predetermined amount ΔDG is a reference amount for determining whether or not the electrical device whose electrical load has been reduced requires supplementary power from the battery 19 in addition to the power supply from the generator 20 during its operation. In other words, the amount of change ΔD[n in the electrical load protection term or the predetermined amount ΔD (if smaller than 1, the battery 1
9 is exhausted and the electrical load of the electrical device has disappeared, but as mentioned above, the output W! is in full power generation state! L machine 2
It is determined that a load of 0 is continuously applied to the engine. If the determination result in step 35 is negative (No), that is,
If the absolute value of the change amount ΔDcn of the electric gL load is smaller than the absolute value of the predetermined amount ΔDa, it is determined that the battery 19 described above is not consumed, and the feedback mode type D p + n value is changed to the feedback mode described above for the reason described later. Mo 1
Step 36) then proceeds to step 33 to set the valve opening duty ratio DOUT of the control valve 6 to the predetermined value Dx (Dp+) instead of the value calculated by .
It is set as the sum of the n value and the current electrical load term Dcn. The predetermined value Dx sets the engine rotation speed Ne to the upper and lower limits N14 of the target engine rotation speed when no electrical load is applied to the engine. This value corresponds to the amount of auxiliary air required to compose the poem between Nl-. In step 36, this predetermined value Dx is fed back to the 7-value D p I
The reason for replacing it with n is as follows. Electrical load term D E
As mentioned above, n is provided to prevent the engine speed from decreasing by increasing the amount of auxiliary air commensurate with the electrical load when the electrical device is turned on, and this electrical load term D E In reality, n is set somewhat larger than the value corresponding to the electrical device 11 in order to prevent the engine speed from decreasing, taking into account the clogging of the filter and the product variation of the control valve 6 shown in FIG. . For this reason,
When the electric device is turned on, a somewhat excessive amount of auxiliary air is supplied to the engine, and the engine speed may exceed the upper limit value NH of the target engine speed. In such a case, the feedback modes Dp+nIJ'' are decreased in order to reduce the engine speed Ne between the upper and lower limits of the target engine speed N o and N + -. In this state, the electrical load is turned off. Since the electric load term D[n, which is a constant, is no longer applied, the amount of auxiliary air supplied to the engine when the electric load is turned off (corresponding to the decreased D p + n value) is calculated by changing the engine speed Ne to the target rotation speed. It becomes insufficient to maintain the target engine speed at the upper and lower limits N ++ , N t , and the engine speed Ne suddenly decreases, and is then returned to between the upper and lower limits N It , N l− of the target engine speed by feedback control. In order to prevent a sudden decrease in the engine speed, the D p Nl value is replaced with a predetermined value Dx in step 3G. If the determination result in step 35 is affirmative (YES), that is, the electric load term decreases. If the absolute value of E It is larger than the absolute value of the predetermined amount ΔD6, it is determined that the battery j9 is exhausted, and in step 37 L) P l
The value obtained by subtracting the amount of decrease ΔDE11 from the n value (20p +
n-I) "++ ++) E n -1) newly [)
Let p l be the Tl value. Then, the valve opening duty ratio D
o u 1 is calculated according to equation (1) above (step 33). As a result, the valve opening duty ratio D o UT becomes the sum of the D p In value calculated in step 25 or 31 and the previous electric load term DE IN-1. Namely. Does it emit even if the electrical device is turned off? [When the machine 20 is still in full power generation state, the valve opening ratio D o
u·I can be maintained at the value when the electrical device is in the on state (Sn in FIG. 1(c)). Also, the Dp+opening price set in step 37 is the Dp for the next loop.
p + n −r value and used in (step 25
Or 31), the D o u・1 value after the next loop is calculated from the DOυ1・value at the current loop in steps 28 and 2.
It will gradually change according to the ui component ΔD+ and the proportional term ΔDp of 9, and the engine @ rotation speed Ne will be as shown in Fig. 1(d).
There will be no change as shown by the broken line. Next, in step 38, the duty ratio DOL of the - connected quantity valve is determined.
It is determined whether I T is greater than zero, and if the determination result is negative (NO), it is determined whether the Do 4+·r value exceeds 100% (step 39). If this determination result is negative (No), that is, the Doll value is 0≦D.
If OUT≦100, the execution of the current loop of the program is terminated, and the control valve 6 is controlled based on the one 014T value at that time. If the determination result in step 39 is affirmative (YES), that is, if the [l o II T value exceeds 100%, n
o u ・r = ] When set to 00, both D p
Ir+=]00-1) +: Set to r+ (step 40), and the execution of the current loop of the program is ended. In step 40, D o II T = ],
OO is set as the calculated value of the valve opening duty ratio D o II T or D o u depending on the operating condition of the engine.
- r > 100, and in the second case, even if the amount of auxiliary air required by the engine is a value corresponding to such a calculated value, this calculated value is an impossible value due to the operation of the control valve 6. Therefore, this is to prevent any inconvenience from occurring in the control of the control valve 6 that is executed depending on the calculation result. Also, in step 110, D p + n = 100
The reason for setting D E 11 is as follows. As illustrated in FIG. 6, immediately after the pipe is started, the engine temperature is low and the lubrication resistance of the sliding parts is high, so the mechanical load on the engine is large. In this state, the electrical device turns on (Fig. 6(a)) and Dp+
The DEn value is added to the n value and the valve opening tute ratio D o +
, r t is set to a value larger than 100%, the amount of auxiliary air required by the engine exceeds the maximum amount of auxiliary air that can be supplied by the control valve 6, so the engine speed N c is set to a value larger than 100%. Sufficient auxiliary air is supplied to the engine between the upper and lower limit values NH and NL of the number, and the engine speed Ne does not return to the lower limit value NL (Figure 6 (C).
)). In such a case, Dp, . The value gradually increases to exceed 100% by the calculations in steps 27 to 31 in FIG. 5(a) (the break π in FIG. 6(b)). On the other hand, as the engine warms up, the lubricating resistance of the sliding parts decreases, so the mechanical load on the engine gradually decreases and the engine speed Ne increases F/. When the engine rotation speed Ne exceeds the target engine rotation speed upper limit NH, the D'p+n value starts to decrease, but as mentioned above, Dp
If the In value exceeds 100%, even if the Dp+n value decreases, the actual amount of auxiliary air starts to decrease at D.
This is after the OIJ T value becomes 100% or less. Therefore, the engine speed N'e has a DOUT value of 1. O0
% (Figure 6 (c)).
) dashed line). In order to eliminate this inconvenience, when the valve opening ratio DOIJT exceeds 100%, Dp
It is set as In=]0O-DEn. With this setting, when the engine speed Ne exceeds the upper limit value NH as described above, the amount of auxiliary air can be immediately reduced as the Dp+n value decreases. If the above-described determination result in step 38 is affirmative (YES), that is, if the D o UT value is smaller than zero, the process proceeds to step 41, where Do UT = O is set and D p In = O. Set this and end the execution of the current loop of the program. Do I in step 41
Setting I T = O is the above-mentioned DOUT〉1
00, the calculated value of the valve opening duty ratio DO11T becomes DoL+1 depending on the operating condition of the engine.
This is to prevent any inconvenience from occurring in the control of the control valve 6 even in such a case. Also, D.O.
The reason why the Dp+n value is simultaneously set to zero when setting UT=O is as follows. Now [) o u T:
If the operating state continues such that N e ) N H even if it becomes 0%, only the calculated value of Dp+n will become an excessively negative value over time, but after that, when an electrical load is added, the predetermined electrical load Although the term DE is added, Dp+n is calculated using an excessively negative value, so D
o u T==Dp In+D, +: is still a negative value and is calculated as Do 1J T = O, and air is not replenished to compensate for the increase in engine load. This causes a rapid decrease in Ne. However, I) o II
T: 0 but at the same time vl] Do not set 10=0,
lt, if electricity (゛(Even if a load is added, D o
This is because u T takes the value of the predetermined electric load term DE, so that the above-mentioned inconsistency can be prevented. In addition, in the above-mentioned embodiment, the Nli auxiliary low air control placed in the air passage 8 Although the intake air amount of the engine is adjusted by controlling the valve 6, the present invention is not limited to this, and any device may be used as long as the amount of intake air of the engine can be adjusted with precision.
For example, the throttle valve opening degrees may be directly controlled. Further, instead of controlling the actuation amount of the control valve as the duty ratio of the valve opening time of the control valve as in the above embodiment, the valve opening degree may be controlled by 4 degrees. As explained above, according to the present invention, the actuation amount of the control valve that adjusts the intake air amount of an internal combustion engine equipped with a power supply circuit that supplies power to a plurality of electrical devices, etc. In an idle rotation speed feedback control method that performs control according to a difference between an engine rotation speed and a target engine rotation speed, an on-off state of each of the electrical devices is detected, and the operating amount is determined based on the detected on-off state. and correcting the actuation amount while the at least one electrical device changes from on to off;
When the amount of change in the correction amount is smaller than a predetermined value, the operating amount before the change in the on-off state of the electrical device is maintained, so that the electrical device changes from the on state to the off state. At the time of transition, an amount of air commensurate with the actual engine load can be supplied to the engine regardless of the state of battery consumption, and a sudden decrease in engine speed can be prevented.

[Brief explanation of drawings]

FIG. 1 is a timing chart 1 showing the method of the present invention during the eye 1 rotation speed fee 1 to hack control of an internal combustion engine. ) shows the change in the state of the battery output voltage, as shown in the same figure (c
) is the valve opening tute ratio of the auxiliary air control valve D OII T
Figure 2 shows the overall configuration of an internal combustion engine control system to which the method of the present invention is applied, and Figure 3 shows the overall configuration of an internal combustion engine control system to which the method of the present invention is applied. 2
The electronic circuit diagram in the electronic control unit (ECU) shown in the figure, Figure 4 is a flowchart of the progera 11 that calculates the electrical loads Dεn, and Figures 5 (a) and (b) are the flowchart of the auxiliary air control valve using feed bank control. Flowchart 1 of the program that calculates the valve opening duty ratio D o UT
・, FIG. 6 shows that the calculation result is 1. This is a timing chart showing the control method when O0% is exceeded, in which (a) shows the on-off state of the electrical device, and (b) shows the open duty ratio D.
o 117 , the feedback modes Dp+n, and the electric loads DEn, and (c) of the same figure is a chart showing the changes in the engine speed Ne. 1. Internal combustion engine, 3. Intake pipe, 5. Slot I
～Le valve, 6...Auxiliary air control valve, 8・Air passage, 9
・Electronic control unit 1~. 10...Fuel injection 4
t, 16.17, 18...Electrical equipment, 19...Battery, 20...Generator, DOLIT...Valve opening Chuchi r ratio, Dp+n/Feedback modes, DFn...
Electrical loads, ΔDa... Negative predetermined amount. Applicant Kiguchi 1 Giken Kogyo Co., Ltd. Agent Patent Attorney Okibe 1Ii2hiko Figure 4, Figure 5 (a)

Claims (1)

[Claims] 1. The operating amount of a control valve that adjusts the amount of intake air of an internal combustion engine that is equipped with lJi number of electrical devices and a power supply circuit that supplies electric power to this JL, etc. is calculated based on the actual engine rotation during idling. In the idle rotation speed feedback control method, the idle rotation speed feedback control method performs control according to the difference between the engine rotation speed and the target engine rotation speed, the on-off state of each of the electrical devices is detected, and the operating amount is corrected based on the detected on-off state. When the at least one electric device changes from on to off, the amount of change in the amount of correction is calculated, and when the amount of change is smaller than a predetermined value, the electric Turning on the device
1. A method for feedback controlling an idle rotation speed of an internal combustion engine, the method comprising maintaining the operating amount before changing to an off state. 2. The internal combustion engine according to claim 1, wherein the predetermined value of the amount of change is a value corresponding to an increase value of intake air corresponding to an electrical load to which electric power is supplied from the battery during idling. Engine idle speed feedback control method.