JPS6293453A - Control method for idling speed of internal combustion engine - Google Patents

Abstract

PURPOSE:To shorten or eliminate the period of reduction of engine speed by adding a prescribed value for a predetermined time onto the electric load correction term when the electric load connected to an AC generator ACG increases, thus reducing the response delay time for the supplied air quantity. CONSTITUTION:In an electronic controller 40, if the engine speed is less than the upper limit revolution speed for the idle feedback control, the voltage value corresponding to the value of the field current of an AC generator ACG17 detected by a field current sensor 19 is read. The read-out value in correspondence to the voltage value through the searching for a table is corrected by adding a prescribed value for a predetermined time or until the increase of the electric load stops, and the electric load correction term is obtained. Since a control valve 30 installed into a bypass passage 31 is controlled by the solenoid current instruction value which is calculated by using the electric load correction term, the response delay time for the increase of the air quantity in the course starting from the bypass passage 31 to a cylinder 35 is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for controlling the idle speed of an internal combustion engine, and particularly to a method for controlling the idle speed of an internal combustion engine. The present invention provides a method for controlling the idle speed of an internal combustion engine, which can reduce the engine speed increase (decrease) to a minimum.

(Prior Art) Conventionally, a fuel cell installed in an intake passage of an internal combustion engine has been used.
During so-called idling operation, in which operation is continued with the thrower valve almost closed, the intake air speed of the internal combustion engine is controlled by a control valve installed in the bypass passage that communicates the upstream and downstream of the thrower valve. This controls the engine speed (idle speed).

This idle speed control method is detailed in, for example, Japanese Patent Application No. 137445/1982, but an outline will be given below.

FIG. 5 shows the configuration of a conventional idle speed control device for an internal combustion engine. This fifth
The figure shows an internal combustion engine in which a 1-t blade 39 is provided between the valve 32 and the injection nozzle 3/1 in order to obtain high output (9: applied no-fiddle rotation). An example of number control equipment is shown.

In the same figure, the intake air velocity in the intake manifold 33 during idling when the stop valve 32 is in a wide-closed state is such that the upstream and downstream of the stop valve 32 are communicated with each other. Control valve 3 provided in bypass passage 31
0i, controlled by 2, 3, this control valve 30 is determined according to the current flowing through the moon tunoid 16, 1, fuel from the injection nozzle 34 1' + 1 injection 0 = I The octopus is known '=F3 to the intake manifold 33 by means of
G-J intake air speed (determined accordingly).

By repeating the screw 1 hem 3ε3G in the cylinder 35, the rotational force of the crankshaft 36 can be changed by (). A pulse is generated when the angle reaches 90 degrees before top dead center. In other words, the TDC sensor 5 outputs the same number of pulses (hereinafter referred to as TDC pulses) as the number of cylinders every two revolutions of the crankshaft 36, and supplies them to the electronic control unit 40.

The engine speed counter 2 detects the engine speed by timing the interval (Me(n)) of TDC pulses output from the TDC sensor 5, and electronically outputs a digital engine speed signal corresponding to this. It is supplied to the control device 40.

Air conditioner't (AC sensor) 8 (Y,) When the near air conditioner is turned on, an air conditioner operation signal is supplied to the electronic control unit 40.

The throttle opening sensor 6 supplies a throttle opening signal as a digital signal to the electronic control unit/10.

The AT position indicator 7 outputs a D1 non-range detection signal when the automatic transmission AT's rector position is in the D range, and outputs an Nll range output signal when it is in the 2l-1 range (N>range). Electronic control system M
'1 Supply to 0. The 2-power Ty'ring sensor ([)S sensor) 9 supplies a power steering operation signal to the electronic control device 40 during power steering operation. Note that the operation signal may be a digital steering angle signal corresponding to the turning angle of the steering wheel.

An AC generator (hereinafter referred to as ACG) 17 is connected to a crankshaft 36 by a belt 18, and can generate electricity by rotation of the crankshaft 3G.

The electric power generated by the AC017 is supplied to the electric load 20.The field current of the AC CG 1 7 is detected by the field current , the detection signal is transmitted by the electronic control device M710
supplied to

The electronic control unit 7'IO is the rear 3? The current flowing through the solenoid 16 is controlled in such a manner that the current flows through the solenoid 16.

In the conventional idle speed control method, the electronic control device 40 shown in FIG. 5 basically calculates the solenoid current command value I cmd using the following equation (1).

Jcmd = CIfb(n) 1Ie 1Ips1l
at 10 ac)
It is a term. Note that (n) indicates the current value.

The calculation contents of steps 341 to 346 in FIG. 6 are as follows.

Step 841... Reciprocal number (period) of engine rotation speed,
Alternatively, the amount Me(n) corresponding thereto is read.

Step 342...The read Me(n) and
The reciprocal of a preset target idle rotation speed or the deviation ΔMef from the corresponding value Mref is calculated.

Step S43... Said Me(n), and said M
Previous measurement value Me in the same cylinder as e(n)
(If the engine is a 6-cylinder engine, Me(n-
6) Calculate Me to the difference in (i.e., the rate of change of the period).

Step 5714...Using the above ΔMe and ΔMef1, integral term control gain K11l+, example term control gain Kl)m and differential term control gain l(dm), calculate the integral term ■11 proportional term 111i13 and differential term Id, respectively. It is calculated according to the formula shown in the figure.The above-mentioned control gains are obtained by reading out those stored in the memory of the electronic control device 40 in advance.

Step S45-I ai(n), Iai(n
-1), the integral term 11 obtained by 1q in step 5471 is added. Note that ai(n) is the next Iai
(n-1), so it is temporarily stored in the memory.

However, if it is not stored in memory yet, ra
A numerical value similar to t may be stored in the memory in advance, and the numerical value may be read out as 1ai (low 1).

Step S46...Ta calculated in step S45
It) and Td calculated in step S44 are added to 1(n), respectively, and the feedback control term 1 f
b(n).

The contents of each term other than I fb(n) in equation (1) are as follows:
It is as follows.

Ie: Addition correction term (hereinafter referred to as electrical load correction term) that adds a scheduled value according to the load of the ACG 17.

Ips: Addition correction term that adds a scheduled value when the power steering switch is turned on.

Iat: Addition correction term that adds a scheduled value when the selector position of the automatic transmission AT is in the drive (D) range.

−〇 − ■aC: Addition correction term that adds and reverses the scheduled value when the air conditioner is activated.

K pad: Multiplication correction term determined according to atmospheric pressure.

Note that I cmd in equation (1) is calculated according to a TDC pulse generated by a known means when the piston of each cylinder reaches 90 degrees before top dead center.

The solenoid 16 has Ic calculated by the above formula (1).
Controlled according to noJ.

Now, the electric load correction term Ie expressed by the Icmd output type and output type shown in equation (1) is set to increase as the field current of the ACG 17 increases. The reason is as follows.

That is, for example, when a certain rotation speed is selected as the target idle rotation speed and idling operation is performed, for example, when an electric load switch such as a headlight is turned on and the electric load increases, the field coil of the ACG 17 is The flowing current increases.

As a result, the load on the internal combustion engine increases and the engine speed tends to decrease, so in order to suppress this, the electric load correction term 1e is increased, and ■C11ld, that is, the intake of the internal combustion engine The aim is to increase room air speed and output.

Of course, even if the electrical load correction term Ie is set successfully, the feedback control term 1f will change due to the decrease in engine speed.
Since b(n) changes, the engine speed is set to a substantially constant value.

However, the control gain (in Fig. 6: m, Kpm and l(dm) for calculating the 1 fb(n) is
Considering the stability during steady idling operation, it is usually set relatively small, so only the I fb[n) term
When attempting to control cmd, the engine speed may drop temporarily when the electrical load on the ACGI 7 increases.

On the other hand, by incorporating the above 1e, which changes according to the field current of the ACG according to -11=, into the Icmd output type shut-off, the rotational speed of the engine when the f1 load of ACGI7 increases and 11 It is possible to reduce the deviation from the target idle rotation speed and quickly bring the engine rotation speed to the target idle rotation speed.

Moreover, the electricity 11 a:+sleeve i' [ITj I (!
4. t, Actual (7) J'l-, 7 It is corrected to J, which increases as the engine rotational speed Ne increases. Lee
f, f, [[The target idle speed is, for example, when the air switch 1- is turned on and the electrical angle of the I, 2, 8 CG increases rapidly. In order to increase the power generation capacity, a high number of rotations is selected. In this case, for example, if the current flowing through one coil of the ACG is constant, the rotational speed of the ACG will be Chi-
Since the ACG power generation amount is larger when the engine speed is higher, the electric load correction term le is increased in relation to the increase in the target idle speed, and the combustion energy This is because it is necessary to increase lj.

(Problems to be Solved by the Invention) The above-described conventional techniques had the following problems.

Generally, when the opening degree of the control valve 30 provided in the bypass passage 31 is increased to increase the amount of air passing through the bypass passage 31, the increase in the amount of air is:
It reaches inside the cylinder 35 with a certain time delay.

In detail, as the field current of 80G17 increases, the value of the electric load correction term He, that is, the value of lcmd increases, and even if the opening degree of the control valve 30 increases, the bypass The increased amount of air passing through the passage 31 is not immediately supplied into the cylinder 35 as an increased amount of air-fuel mixture, but is supplied into the cylinder 35 with a certain time delay.

This time delay is due to the time delay of 1. The longer the length of the manifold 33, the longer the number of people will be.
As shown in the figure, in order to obtain high output, a chamber 39 is provided between the throttle valve 32 and the cylinder 3F.
゛) When someone is being talked to, one becomes very personable.

Therefore, the electric load correction term ■e whose value changes according to the change in the one-no-yield current of ACGI 7 is
Even if you enter the Iid equation, immediately after the electrical load correction term ie changes, the electrical load correction term ■e1, that is, I
In the transient time region until the dark air-fuel mixture corresponding to cmd is supplied into the cylinder 35, the cylinder 35
Since the air-fuel mixture is not drawn sufficiently within 4 days, and as mentioned in 1) above, the control gain of feedback control term 1 fb(r+) is small, so the engine rotational speed may drop. .

As a result, engine idling becomes unstable (J).

The present invention solves the problems described above (1-Lotome 6.-)
It has been done.

(Means and effects for solving the problem) In order to solve the above problem, the present invention provides an electric load correction term (e) when the electric load connected to 80G17 increases. Alternatively, a predetermined value is added until the increase is eliminated, and as a result, a value exceeding the solenoid current command value (cmd) set according to the increase in the electrical load is set as the electrical load increases. After the amount of air flowing into the bypass passage 31 increases, the amount of air that should be increased in accordance with the increase in electrical load is actually output to the cylinder for a scheduled time after the increase in electrical load or until the increase is eliminated. It is characterized in that it has the effect of shortening the delay time until it is supplied into the container.

(Example) The present invention will be described in detail below with reference to the drawings.

FIG. 1 shows the above-mentioned (1) of the processing steps of the idle speed control method for an internal combustion engine to which an embodiment of the present invention is applied.
) is a 7-day chart showing the procedure for extracting the fraud correction term re set according to the field current of the ACGI 7 according to the formula IcmtJ.

This flowchart is executed, for example, in the electronic control device 4o of the idle speed control device shown in FIG. The above calculation is performed from TDC sense to T I
) Executed every time a C pulse is output.

First, in step S1, the engine speed Ne of the engine is set to the upper limit speed Necal (for example, about 200OR) at which idle feedback control should actually be performed.
PM) is exceeded or not.

If it exceeds Necal, it is assumed that idle feedback control is not performed, and in step $2,
Electrical load correction term Ie is set to 0, -16=The process ends. If it is less than Necal, the process moves to step S3.

In step S3, the current value of the field current of the ACGI 7 detected by the field current sensor 19 in FIG. 5 or the voltage value corresponding to the field current (hereinafter simply referred to as voltage E1) is read. This voltage E1
is an AD-converted numerical value. Note that n here is a value that is incremented by 1 each time the process is performed, and E
1 (n) indicates the latest value (current value).

Although not shown, the voltage E1 is stored in the memory of the electronic control unit 40, and its stored contents are retained until the process is repeated at least r times, as will be roughly described later regarding step S8. .

Next, in step S4, E shown in FIG.
1 to iex table and reads and stores the iex corresponding to the above "1(n).The iex is J:Uni, ACGI 7's This is a numerical value used when excluding the electrical load correction term He.

Note that the above-mentioned tex is a value that is used as it is as the electric load correction term Ie in the conventional idle speed control method for an internal combustion engine.

In step S5, the E1 (b) is 80G1
7 is close to full power generation, the AC
The voltage value E 1 (I
It is determined whether or not it exceeds O3.

If E 1 (n) does not exceed the voltage value IE 1 oos, the process moves to step 87 and the voltage value E1
If it exceeds gos, the process moves to step s6.

In step S6, step S10. S
It is determined whether the flag [os set at 16 or 818 is 1 or not. If the flag Fos is 1, the process moves to step S12, and if the flag OS is not 1, the process moves to step S7.

In step S7, it is determined whether the TDC pulse has been output r times after the rotational speed Ne of the engine becomes equal to or lower than the rotational speed Necal described in connection with step S1.

If the flag "O31 step 311
The force run of the electrical load correction term Ie, which will be described later with respect to]・value 1
eCnt and an overcoat value Teos, which will be described later regarding step S14, are each set to O.

Further, in step 819, step 82
1 as I eX(n) used in step S
iex calculated in step 4 is set. Then, the process moves to step 820.

In step S7, whether the engine rotational speed Ne or N
If the TDC pulse has been output at least once since eCaI or less and '/, r, then in step 88, the TDC of the F 1 (n) and the E 1 (n) is output.
Whether the difference from the voltage r pulses ago [:1, that is, 1(n-r) exceeds the predetermined value ΔE1 or not, is -, but if the value of the voltage [1 is suddenly It is determined whether the

If the predetermined value Δ[1 is not exceeded, the process moves to step 316, and similarly to step 318, “os
, reent, and 7 eos is 01. : Set. Then, in step S17, (Jll), then Hex (b), which is expressed by equation 1 (2), is calculated.

[X(n) = ieX XΔ/13 +I ex(n-1) x (C3-△) / [-3
-...-<2) In equation (2), iex IJ, the value calculated in step 84, lex(n-1) is the previous value of the cut-out dimension exponent lex(n). 3. Also, △
and C3 is a positive number set to fT (this is set to -20), and B is chosen to be much larger than A.

After that, the process moves to step S20.

In step S8, the F 1 (n) and E
1 (n-r) exceeds the predetermined value ΔE1, then step S91. Leave T,
It is determined whether the flag [O3 is O or not.

If the flag Fos is O, the flag "os" is set to "1" in step S10. Then, in step S11, He count 1 shift 1 ecnt
Set to ecnto.

This count candy 1 ecnto is the electrical load correction term le
When the A-basic value Δ1 eos is added to the A-basic value Δ1 eos, from the time of addition (when the air amount in the bypass passage increases quickly), the required air-fuel mixture (from the air amount in the bypass passage at the time of the addition to the value ΔI This corresponds to the time it takes for the amount of air (compound gas) obtained by subtracting the amount of air corresponding to eos to be supplied into the cylinder.

This method 1 ~ value r ecnto is
Δ1eos, a value rclj determined by the shape, size, etc. of the intake pipe of the internal combustion engine.

This sdell811 smell-(,1e count 1 shift 1
eerit is I ecnto 4. : When riQ is constant, the Karan 1-value I eer+to G;t, which will be described later-
Zoor Tsubu 513fj-Hey C1TDC Pulse 1 every time! /° cotton is reduced. That is, the period 1 to 1 ec and the corresponding period are measured.

Then, until the above-mentioned period has elapsed, in step 314, which will be described later, Δl eos is set as the oversight 1-h (direct Ieos), and in the slave block 822, the above-mentioned Oversight,
finΔI eos is added to −1 to calculate the electrical load correction term 1e.

In the step S9, the flag FO3 is not 0, that is, the flag FO3 is 1 in the step 810.
If it is determined that J is set in step 811, then in step 812, J
It is determined whether e count value 1 ecnt has become O or not.

If the ie count value 1 ecnt is O, the process moves to step S16; if it is not 0, the process moves to step S81.
Move to 3. In step 813, the e count value Iecnt is subtracted by 1, as described above.

After the process passes through step 811 or 813, in step 814, the overshoot value ■e
Δ(eos is set as O3.

Then, in step 815, iex calculated in step S4 is set as Iex(n).

In step S20, M as shown in FIG.
A search of the ref-ke table is performed.

= 23- The above M ref is the reciprocal number (i.e. period) of the target idle rotation speed or an equivalent value, and ke is
Step 821 (this is an east line correction term that will be described later).

The M ref is determined according to the temperature of engine cooling water of the engine. Through the table search in step 820, the value of ke corresponding to M ref determined according to the temperature of the engine cooling water is read.

In step 821, the step S15゜S1
Iex(n) set in step 7 or S19 is multiplied by the power bond correction term read out in step S20, and the product is defined as IeO.

Then, in step 322, the overshoot value 1 eO3 set in steps 5171, 316, or 818 is added to the ■eO, and the result is defined as the electrical load correction term re of the ACG 17.

Note that in step 816 or 818, the overcoat value 1 eos is set to O, so in this case, the electrical load correction term Ie is actually IeO.

After that, the processing is completed.

The present invention provides the electrical load correction term I calculated in this way.
Using e, a solenoid current command value of 1 cmd is calculated based on the closing equation shown in equation (1), and the control valve 30 provided in the bypass passage 31 is controlled.

Next, the electric load correction term (e) obtained by the above-mentioned embodiment is the electric load correction term (e) obtained by the conventional method.
The specific difference between the two will be explained with reference to FIG. 4 and FIG. 1.

FIG. 4 is a graph showing an example of the electrical load correction term Ie that changes depending on the number of elapsed TDCs. In FIG. 4, the broken line curve represents the electrical load correction term Ie calculated by the embodiment of the present invention shown in FIG. The iex searched in S4 according to the voltage E1 is shown.

Note that the dashed line drawn in FIG. 4 indicates the voltage value E 1 (iex corresponding to 10S) explained regarding step S5
shows the value of

As is clear from FIG. 4, when the load of the ACG 17 increases from a state where the field current of the ACG 17 is relatively small and the number of elapsed TDCs reaches the maximum, the increase increases to the degree shown in step S8. If the value exceeds ΔI eos, ΔI eos is set as the overcoat value until 1 ecnto has elapsed from the time T through the processes of steps S9 to S14 and 822 in FIG.
eO3 is added to IeO.

Therefore, after the electrical load of the ACG 17 increases at a rate of ``-'', the current command value Icmd corresponding to the increase is
Since a value exceeding 1 is output for a period of l ecnto, the response time to an increase in air amount from the bypass passage 31 to the inside of the cylinder of the internal combustion engine is shortened.

After the A-base l~value Δ1 eos is added, the addition is performed depending on whether the voltage t1 of ΔCG17 or the voltage (if'
While f E 1 gos is exceeded, the electric current 1f [1
This is done over the course of IeCntO, regardless of changes in IeCntO.

If the voltage [1 is less than the voltage value F100S, when the rate of increase of the voltage [1 is less than the rate of increase in step S8,
The coastline of ■eos to the overcoat value is stopped (steps S5 and 38).

Note that when the voltage [1 does not show a large variation range (region [<) in FIG. 4], averaging of 1 ex (n) is performed using equation (2) in step S17. This is based on the following reasons.

Depending on the type of electrical load, the load characteristics may fluctuate at relatively short intervals, but if such an electrical load is connected to the ACG, or if the engine is in idle-feedback operation. If the -F engine rotational speed is fluctuating when performing the -F engine rotation speed, the voltage may become larger or smaller depending on the detection timing of the voltage (the value of 1 is relatively 1). .

However, even if the electric current 1f [1 changes 1) with a very short cycle,
The change in the amount of air flowing from the bypass passage into the cylinder cannot follow the above-mentioned cycle, so the voltage "
It does not make much sense to accurately calculate the electric load correction term 1e with respect to the candy of 1).

Therefore, when the electric load 1 does not undergo a very large deviation, it is assumed that the electric current f1 is constant, and the change in the electric n1 is made small.
To calculate the equalization 1 electricity t] mercenary iF Ii'l IO, it is i;':j.

As a result, it is accurate (, - electric f
-1-1 It is possible to perform idle feedback control (j) which is 51 better than calculating the positive correction e.

−28= Also, in step S21, ■eX(n) is multiplied by the multiplication correction term ke set according to the reciprocal number Mref of the target idle rotation speed, which increases the power generation capacity of ACG. GJ is caused by the need to increase the energy (torque) to be supplied to the ACG when the target idle speed increases.

(Effect of the invention) .

As is clear from the above description, according to the present invention, the following effects are achieved.

That is, after the electrical load increases, more air than the amount of air in the steady state corresponding to the electrical load is passed through the bypass passage for a scheduled time 1! Since the solenoid current command value Icmt1 is set, the time from when the electrical load increases and the amount of air flowing into the bypass passage increases until the actually required amount of air is supplied into the cylinder is Delays will be shorter.

As a result, it becomes possible to know the period during which the engine rotational speed drops, or to eliminate the drop.
The life of the battery will not be shortened or reversed due to unstable cycling or discharge of the charge stored in the battery.

[Brief explanation of drawings]

FIG. 1 shows the procedure for calculating the electric load correction term fie in the processing procedure of an embodiment of the present invention. Figure 3 shows the Mref-ke''7-pull graph.
Figure 4 is a graph showing an example of the -16 electric negative pre-correction term e that changes depending on the elapsed TDC number, Figure 5 is a schematic 7n diagram showing the configuration of the idle speed control device, and Figure 6 is feedback control. 3 is a flowchart showing a procedure for calculating the term Ifb(n). 16... Solenoid, 17... AC digital relay,
19...Field current sensor, 20...Various electric loads, 30...Control valve, 31...Bypass passage, 3
2...Slot 1~le valve, 35...Cylinder, 40...
...Electronic control device agent Patent attorney Michito Hiraki and 1 other person No. 3111 (1 ↑ Figure 4)

Claims (4)

[Claims] (1) A control valve that is provided in a bypass passage that communicates between the upstream and downstream of the throttle valve of the internal combustion engine and controls the amount of air flowing through the bypass passage, and the field current value of the AC generator that is driven by the internal combustion engine. and a feedback control term determined based on the deviation between the target idle speed and the actual engine speed during idling operation of the internal combustion engine, and at least the feedback control term detected by the detection means. Depending on the electrical load correction term determined based on the field current value,
In the method for controlling the idle speed of an internal combustion engine that controls the control valve, when the field current detected by the detection means increases, a predetermined value is set in the electric load correction term for a predetermined period from the time of the increase. A method for controlling the idle speed of an internal combustion engine, the method comprising: adding the idling speed of an internal combustion engine. (2) The method for controlling the idle speed of an internal combustion engine according to claim 1, wherein the addition of the predetermined value is performed when the field current increases by a predetermined rate or more. (3) According to claim 1 or 2, the addition of the predetermined value is performed when the value of the electrical load correction term increases in accordance with an increase in the field current. The method for controlling the idle speed of an internal combustion engine as described above. (4) The internal combustion engine according to any one of claims 1 to 3, wherein the addition of the predetermined value is canceled when the field current no longer increases. Idle speed control method.