JPH02291448A - Intake air amount control device for internal combustion engine - Google Patents

Abstract

PURPOSE:To ensure the prevention of knocking by enlarging the increment of an intake air amount all the more when ignition timing is at an advance side in the internal combustion engine wherein the intake air amount is increased upon the application of an external load and the ignition timing is corrected toward the advance side during the running of the engine at the predetermined speed. CONSTITUTION:An idling speed control valve(ISC valve) 22 is provided at a bypass passage 21 bypassing a throttle valve in an intake air passage 3. When an external load such as an air conditioner and a power steering unit are connected to an engine 10, ISC valve 22 is opened with CPU and an intake air amount is increased, thereby preventing an engine speed drop. Also, when the operation of the engine 10 is in the predetermined mode as in the case of idling operation, ignition timing is corrected toward an advance side, and an idling speed is thereby made to near the target number of revolutions. In the aforesaid control device, an intake air amount is increased all the more when the ignition timing is at the advance side, and the occurrence of knocking is thereby prevented properly.

Description

Detailed Description of the Invention (Field of Industrial Application) This invention provides an ignition correction means for advanced control of ignition timing for idle stability, and an increase in the amount of intake air when external loads such as air conditioning and power steering are manually operated. The present invention relates to an intake air amount control device for an engine, which includes both a controlling means and an increasing means.

(Prior art) Conventionally, when the idle speed is lower than the target speed,
The ignition correction means (see Japanese Patent Application Laid-open No. 121843/1984) brings the idle speed closer to the target speed by feedback controlling the ignition timing to the advance side, and the external load is A known method is to increase the intake air amount by a predetermined amount for the purpose of suppressing the rotational drop of the engine when the engine enters the engine.

However, when both of these means are provided, the following problems arise.

In other words, when the ignition timing at idle is being feedback-corrected to the advanced side, if an external load such as the air conditioner or power steering is applied, the engine speed will drop and knocking will occur. .

The occurrence of knocking is based on the characteristic that the lower the engine speed, the more the engine enters the knocking region even if the ignition timing advance is small. This is because the knocking zone occurs due to both the ignition timing being corrected to the advanced side and the rotation drop due to external load input.

(Purpose of the Invention) This invention provides an engine intake engine that can reliably prevent knocking that occurs by positioning the ignition timing on the advanced side in response to a drop in engine rotation due to an external load being applied during idling. The purpose is to provide an air volume control device.

(Structure of the Invention) The present invention includes an increasing means for increasing the amount of intake air by a predetermined amount when an external load is applied, and an ignition ignition controller that corrects the ignition timing to advance when the engine is in a predetermined operating state. An engine intake air amount control device comprising a correction means, the control means increasing the intake air amount by the increase means as the ignition timing of the ignition correction means advances. It is characterized by being an intake air amount control device.

(Effects of the Invention) According to the present invention, when the ignition timing during idling is corrected to the advance side by the above-mentioned ignition correction means, the above-mentioned control means controls the intake by the increase means in response to the external load input. Since the amount of air is increased by a large amount, it is possible to prevent the rotation drop when the external load is input as described above, and to reliably avoid the occurrence of knocking.

(Example) An embodiment of the present invention will be described in detail below based on the drawings.

The drawing shows an engine intake air amount control device. In FIG. 1, an air flow meter 2 is connected to the rear of an air cleaner 1 that purifies intake air, and the air flow meter 2 detects the intake air amount as a voltage change. It is structured as possible.

A throttle body 3 is connected to the rear of the air flow meter 2, and a throttle chamber 4 within the throttle body 3 is provided with a throttle valve 5 as a control valve for controlling the amount of intake air.

A surge tank 6 as an expansion chamber having a predetermined volume is connected to the intake passage downstream of the throttle valve 5.
An intake manifold 8 communicating with an intake boat 7 is connected downstream of the surge tank 6, and a fuel injection valve 9 is disposed in the intake manifold 8.

On the other hand, the above-mentioned intake port 7 and exhaust port 12, which communicate with the combustion chamber 11 of the engine 10 as appropriate, include an intake valve 13 and an exhaust valve 14, which are opened and closed by a valve mechanism (not shown).
Further, an ignition plug 16 is attached to the cylinder head 15 with a spark gap facing the combustion chamber 11 described above.

The exhaust passage 17 communicating with the above-mentioned exhaust port 12 has a zero
Two sensors 18 are disposed, and a catalytic converter 19 (so-called catalyst) is connected to the rear of the exhaust passage 17 to render harmful gases harmless.

Incidentally, while an air flow sensor 20 is attached to the above-mentioned air flow meter 2, a passage 21 that bypasses the above-mentioned throttle valve 5 is provided, and an idle speed control valve 22 is interposed in this passage 21. In the following description, the idle speed control valve 22 will be abbreviated as an IsC valve, and the idle speed control will be abbreviated as IsC.

FIG. 2 shows a control circuit of an engine intake air amount control device, in which the CPU 30 includes an air flow sensor 20, a starter 23,
, test switch 24, idle switch 25, load switch 2 for air conditioners, power steering, etc.
6. Based on the input from the distributor 27, R
The above-mentioned spark plug 16 and ISC/<lub 22 are driven and controlled according to the program stored in the oM28, and the R
AM29 is engine rotation speed data that determines the operating state of the engine 10 to be idle, and idle target rotation speed data N.
O, Minimum guard value data (KAFBMN) and maximum guard value data (KAFBMX) of ignition timing feedback amount at idle, ±5 with respect to idle target rotation
0 0 +pm engine rotation speed predetermined range data, table of corrected air weight mcgfb) corresponding to deviation D between engine rotation speed Ne and target rotation speed No, maximum guard value data for ISC feedback amount, minimum guard value for ISO feedback amount Value data, ISO basic air weight data (G
B), ISC load correction weight data (GL), one-shot load correction weight data (KISB), KISB attenuation rate data, intake air amount increase correction data when the ignition timing is on the advance side at idle, Y1 ignition advance angle Necessary data such as allowable limit point data X near entry into the knocking zone is stored.

Here, when the above-mentioned CPU 30 receives an external load, the IS
an increase means for closing the C valve 22 and amplifying the amount of intake air by a predetermined amount; an ignition correction means for correcting the ignition timing to the advanced side when the engine 10 is in an idling operating state; The more advanced the ignition timing is, the more the intake air amount is increased by the above-mentioned amount increasing means.

The operation of the engine intake air m control device configured as described above will be explained with reference to the flowcharts shown in FIGS. 3 to 7.

First, the first step 3 of the basic ignition timing routine shown in Figure 3.
1, the CPU 30 determines whether or not the air flow meter 2 has failed based on the output from the air flow sensor 20, and if the air flow meter 2 is normal, the CPU 30 executes the next second step 3.
2, while air 7 low meter 2 fails (
(at the time of abnormality), the process moves to another third step 33.

In the second step 32 described above, the CPU 30 determines whether the starter 23 is ON or not, and when the starter 23 is turned ON, the process proceeds to the third step 33 described above, while when the starter 23 is turned OFF after starting, a different operation is performed. The process moves to the fourth step 34.

In this fourth step 34, the CPU 30 compares the engine rotation speed Ne from the distributor 27 with a preset starting rotation speed, for example, 500 rpm, and determines the engine rotation speed Ne from the distributor 27.
When ≦5 0 0 + pm, the process moves to the third step 33 described above, while when N e > 5 0 0 rpm, the process moves to the next fifth step 35.

In the third step 33 described above, the CI"U3Q uniformly sets the ignition timing to a fixed predetermined ignition timing, and then in the next sixth step 36, the CPU 30 drives and controls the spark plug l6 in the starting mode.

In the fifth step 35 described above, the cPU 3o switches the test switch 24 as a manually operated fixed advance angle switch.
is ON or not, and when the test switch 240N, the process moves to the next seventh step 37, while when the test switch 240FF, the process moves to another eighth step 38.

In the seventh step 37 described above, the CPU 30 sets the ignition timing to a fixed advance angle corresponding to the test mode, and in the next ninth step 39, the CPU 30 performs a smoothing calculation of the ignition advance angle, and then in the next tenth step 4o. In step 36, the CPU 30 determines the actual advance angle, and in the next sixth step 36, the CPU 30 determines the actual advance angle.
6 is driven and controlled in test mode.

In the eighth step 38 described above, the CPU 30 determines whether the idle switch 25 is ON or not, and turns the idle switch 25 ON.
When the engine is idling when the idle switch 250FF is ON, the process moves to the next 11th step 41, while when the idle switch 250FF is in normal operation, the process moves to another 12th step 42.

In this twelfth step 42, the cpuao sets the ignition timing corresponding to the engine operating state by normal map control, and in each step 39 and 4036 described above, the CPUAO sets the ignition timing corresponding to the engine operating state.
6 in the normal mode.

In the above-mentioned eleventh step 41, CPU 30i
;t, determine whether it is an ISC feedback zone, [
If it is outside the SC feedback zone, the process proceeds to the above-mentioned twelfth step 42, while if it is in the SC feedback zone, the process proceeds to the next thirteenth step 43, where the ignition timing feedback correction amount during idling is calculated. The subroutine for calculating the correction amount (see FIG. 4) will be described later.

Next, in a fourteenth step 44, feedback correction ffi (THTFB
) (see FIG. 4), the spark plug 16 is driven and controlled in the idle feedback mode in steps 39, 40, and 36 described above.

In other words, advanced control of ignition timing is performed for idle stability.

Next, the ignition timing feedback correction amount calculation routine (subroutine) during idling will be described with reference to FIG.

In a first step 51, the CPU 30 calculates a rotation speed deviation D by subtracting the idle target rotation speed No from the current engine rotation speed Ne.

Next, in a second step 52, the CPU 30 determines whether the rotational speed deviation D mentioned above is positive or negative.

If the current engine rotation speed Ne is higher than the idle target rotation speed No and the rotation speed deviation D is positive, the process moves to the next third step 53.

On the other hand, if the current engine rotation speed Ne is lower than the idle target rotation speed NO and the rotation speed deviation D is negative, the process moves to another fourth step 54.

In the third step 53 described above, the CPU 30 calculates the feedback constant A corresponding to the positive deviation D, and in the fourth step 54 described above, the CPU 30 calculates the feedback constant A corresponding to the negative deviation D.

Next, in the fifth step 55, the CPU 30 compares the above calculation result 8 with the minimum guard value (KAF BMN) of the ignition timing feedback amount at idle, and when the calculation result 8 is smaller than the minimum guard value (KAFBMN), , moves to the next sixth step 56, and in this sixth step 56, the CPU
30 sets the above-mentioned minimum guard value (KAFBMN) to the feedback correction amount (THTFB).

On the other hand, when the calculation result 8 is greater than the minimum guard value (1 (AFBMN)), the process moves to the next seventh step 57.

In this seventh step 57, the CPU 30 compares the above calculation result A with the maximum guard value (KAFBMX) of the ignition timing feedback amount at idle, and when the calculation result 8 is larger than the maximum guard value (KAFBMX), the following The process moves to an eighth step 58, and in this eighth step 58, the CPU 30
sets the above-mentioned maximum guard value (KAFBMX) to the feedback correction amount (THTFB).

On the other hand, when the calculation result A is smaller than the maximum guard value (KAFBMX), K A F B M X > A >
In KAFBMN, when the above-mentioned calculation result A is a value located between each guard value, the process moves to the next ninth step 59,
In this ninth step 59, the CPU 30 sets the above-mentioned calculation result A to the feedback correction ffl (THTFB).

In this way, the ignition timing feedback control corresponding to step 13 in FIG. 3 is executed based on the subroutine in FIG. 4.

Next, the ISC control routine will be explained with reference to FIG.

In a first step 61, the CPU 30 selects the current engine speed Ne and a preset starting speed, for example, 500.
Compared with rpm, N e < 500 rpm
When the start mode is determined, the process moves to the next second step 62, and ISC control corresponding to the start mode is executed.

On the other hand, if N e > 5 0 0 + Ilm, the process moves to the next third step 63 .

In this third step 63, the CPU 30 determines whether the starter 23 is ON or not, and when starting the starter 230N, the process proceeds to the second step 62 described above, while after starting, the starter 23 is turned on? When it reaches F, the process moves to the next fourth step 64.

In this fourth step 64, the CPU 30 determines whether the test switch 24 is ON or not. When the test switch 24 is ON, the CPU 30 moves to the next fifth step 65, and executes ISO control corresponding to the test mode. When it is OFF, the process moves to another sixth step 66.

In this sixth step 66, the CPU 30 determines whether the idle switch 25 is ON or not, and turns the idle switch OFF.
Sometimes, the process moves to the next seventh step 67 and executes ISC control corresponding to the open mode during normal operation (
On the other hand, when the idle switch is ON, the process moves to another eighth step 68.

In this eighth step 68, the CPU 30 determines whether the current engine speed Ne during idling is within a predetermined range of, for example, ±50 O rpm with respect to the target idle speed NO, and detects whether the engine is outside the predetermined range. When the rotation speed fails, the process moves to the seventh step 67 described above, while if it is within a predetermined range, the process moves to the next ninth step 69.

In this ninth step 69, the CPU 30 compares the current engine speed Ne and the idle target speed No.
When e>No, proceed to the next 10th step 70, Ne≦N
When the result is O, the process moves to the next 11th step 71.

In the above-described tenth step 70, the CPtJ 30 determines whether the ISC feedback delay time has ended, and when the delay time has ended, proceeds to the next eleventh step 71.

In this eleventh step 71, the CPU 30 determines whether the increase in the amount of intake air after starting (post-starting increase) has been completed, and upon completion, proceeds to the next twelfth step 72.

In this twelfth step 72, the CPU 30 determines whether or not the intake temperature correction has been completed, and upon completion, proceeds to the next thirteenth step 73.

In this thirteenth step 73, the CPU 30 determines whether or not the dashpot correction has been completed, and upon completion, the next first
Step 4 moves to step 74.

In this 14th step 74, the CPU 30 determines whether the car is a mechanic car or an AT car, and if it is a mechanic car, it moves to the next 15th step 75, and if it is an AT car, it moves to the next 16th step 76. .

In the above-mentioned 15th step 75, the CPU 30 determines whether the gain is decelerating or not, and when the gain is on, the CPU 30 moves to the above-mentioned 7th step 67, while when the non-gain is neutral, the CPU 30 moves to the next 16th step 76, and feedback is performed. Executes ISC control corresponding to the mode.

Next, the ISC feedback routine will be explained with reference to FIG.

In a first step 81, the CPU 30 determines whether or not it is in the ISC feedback zone, and if it is in the ISO feedback zone, it moves to the next second step 82.

In this second step 82, the CPU 30 calculates the rotation speed deviation D by subtracting the idle target rotation speed No from the current engine rotation speed Ne.

Next, in a third step 83, the CPU 30 determines the corrected air weight ffi (g f b) from the table in the RAM 29 based on the absolute value of the rotation speed deviation D described above.

Next, in a fourth step 84, the CPU 30 determines whether the above-mentioned rotation speed deviation D is positive or negative, and when the deviation D is positive, the next fifth
The process moves to step 85, and in this fifth step 85, the CP
U30 is the actual feedback f of the corrected air weight up to the previous time.
Corrected air weight M't (g f b) from fi (GFB)
The current actual feedback amount (GFB) is calculated by subtracting .

On the other hand, if the rotational speed deviation D mentioned above is negative, the process moves to the next sixth step 86, and in this sixth step 86, the CPU 3
0 is the previous actual feedback ffi of the corrected air weight
The current actual feedback m (GFB) is calculated by adding the corrected air weight JR (gfb) to (GFB).

Next, in a seventh step 87, the CPU 30 compares the above calculation result (G FB ) with the maximum guard value of the ISO feedback amount, and if GFB>MAX guard, the process proceeds to the next eighth step 88, and this In the eighth step 88,
The CI'U 30 sets the actual feedback ffi (GFB) to the maximum guard value regardless of the calculation result.

On the other hand, if GFB≦MAX guard, the process moves to the next ninth step 89.

In this ninth step 89, the CPU 30 compares the above calculation result (GF B) with the minimum guard value of the ISO feedback amount, and if GFB<MIN guard, moves to the next tenth step 90, This tenth step 90
Then, the CPU 30 sets the actual feedback amount (GFB) to the minimum guard value regardless of the calculation result.

On the other hand, when the calculation result (G F B) is larger than the minimum guard value, that is, when MAX guard>GFB>MIN guard, the process moves to the next eleventh step 91, and this eleventh step
In the step-up 91, the CPU 30 calculates the above calculation result (G
FB) is directly set as the actual feedback amount (GFB).

Next, the ISO load correction routine will be explained with reference to FIG.

In the first step 101, the CPU 30 determines whether or not it is in the ISC feedback zone, and if it is in the feedback zone, it moves to the next second step 102.

In this second step 102, the CPU 30 adds the above-mentioned actual feedback amount (GF
B) (see Figure 6) to obtain the ISO total air weight f
Calculate fi(GA).

Next, in a third step 103, CPUAO determines whether or not the ignition advance feedback zone is reached, and if it is in the ignition advance feedback zone, the process proceeds to the next fourth step 104.

In this fourth step 104, the CPU 30 turns off the load switch 26 of the air conditioner, power steering, etc.
It is determined whether or not the load switch 26 has changed from OFF to ON, and if the load switch 26 has not changed from OFF to ON, the process proceeds to the next fifth step 105.

In this fifth step 105, the CPU 30 outputs the value of ISO total air weight ffl (GA) as the calculation result of the above-mentioned second step 102 to the ISO valve 22, and performs idle speed control based on the above-mentioned GA value. .

On the other hand, if the load switch 26 is turned from OFF to ON, the process moves to the next sixth step 106.

In this sixth step 106, the CPU 30 compares the ignition advance feedback correction amount during idling with the above-mentioned allowable limit point data Time is the next 7th step 107
In this seventh step 107, the CPU 30 executes normal load correction.

In other words, the ISC basic air weight ffiGB, the actual feedback ffl (GFB), the ISC load correction weight (GL), and the one-shot load correction weight (K I
S B) and ISC total air weight ffi (G
After setting A), in the next fifth step 105, idle speed control is performed based on this GA value, thereby executing normal increase control (load control) of the intake air amount when an external load is input.

On the other hand, in the sixth step 106 described above, the F/B correction ffl>
When it is determined that it is X, the next eighth step 108
In the eighth step 108, the CPU 30 executes load correction to increase the increase in intake air amount by the increase means.

In other words, ■ SC basic air weight (GB), actual feedback amount (GFB), ISO load correction weight (GL), and one-shot load correction weight ffl (KI
After adding the intake air amount increase correction value Y to SB) and setting the sum of these values to ISC}-tal air weight (GA), in the next fifth step 105, the idle is adjusted based on this GA value. By performing speed control, the more advanced the ignition timing of the ignition correction means is, the more control is executed to increase the amount of intake air by the above-mentioned increase means.

In this way, when the ignition timing at idle is corrected to the advanced side by the ignition correction means, the above-mentioned control means increases the amount of intake air by the increase means in response to the input of the external load, so the above-mentioned This has the effect of preventing the engine rotation from dropping when an external load is input, thereby reliably avoiding the occurrence of knocking.

In the correspondence between the configuration of the present invention and the above-described embodiment, the amount increasing means of the present invention corresponds to the fourth step 104 and the seventh step 107 (see FIG. 7) controlled by the CPU 30 of the embodiment, and the following similarly applies. , The ignition correction means performs the eighth step 3 under the control of the CPU 30.
8. Corresponding to the 11th step 41 and the 13th step 43 (see FIG. 3), the control means controls the 6th step 106 under the control of the CPU 30.
, corresponds to the eighth step 108, but the present invention is not limited to the configuration of the above-described embodiment.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a system diagram of an engine intake air amount control device, and FIG.
3 is a flowchart showing the ignition timing basic routine; FIG. 4 is a flowchart showing the ignition timing feedback correction amount calculation routine during idling; FIG. 5 is a flowchart showing the ISO control routine; FIG. 7 is a flowchart showing the ISC feedback routine, and FIG. 7 is a flowchart showing the ISO load correction routine. 10... Engine 3 0... CPU 38... 8th step (ignition correction means) 41... 11th step (ignition correction means) 43... 13th step (ignition correction means) 104... - Fourth step (increasing means) 107... Seventh step (increasing means) 106...
・6th step (control means) 108...8th step (control means) Fig. 2 30...CPU Fig. 4

Claims (1)

[Claims] (1) Equipped with an increasing means for increasing the amount of intake air by a predetermined amount when an external load is applied, and an ignition correcting means for correcting the ignition timing to the advanced side when the engine is in a predetermined operating state. An intake air amount control device for an engine, comprising control means for increasing the amount of intake air by the amount increasing device as the ignition timing of the ignition correction device advances. .