JPS63280857A - Ignition timing controller - Google Patents

Abstract

PURPOSE:To correctly control the ignition timing of an engine even in the transient state of the engine by correcting the output of a means for detecting the intake quantity per intake cycle (A/N) of the engine according to the output of a throttle opening degree sensor, after smoothing. CONSTITUTION:An air flow sensor 13 detects the air quantity inhaled into an engine 1, and a crank angle sensor 17 detects the number of the revolution of the engine 1. An A/N detecting means 20 counts the output pulse quantity of the air flow sensor 13 which is inputted at each prescribed crank angle of the engine 1. Further, an A/N calculating means 21 calculates the pulse quantity corresponding to the output of the air flow sensor 13 which corresponds to the air quantity inhaled by the engine 1, and after AN is made smooth, correction is performed according to the output of a throttle opening degree sensor 25. A control means 22 controls an injector 14 and an ignition coil 19 according to the output of the AN calculating means 24 and each output of the crank angle sensor 17 and a water temperature sensor 18.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an internal combustion engine that detects the intake air amount of the internal combustion engine using an intake air amount sensor, and controls the ignition timing of the internal combustion engine based on the detected output and the engine rotation speed. The present invention relates to an ignition timing control device.

[Conventional technology]

When controlling the ignition timing of an internal combustion engine, a Karman vortex type intake air amount sensor (hereinafter abbreviated as AFS) is placed upstream of the throttle valve, and the intake air amount per intake of the engine "A" calculated from the actual performance of this AFS. The ignition timing of an internal combustion engine is controlled based on /N (also abbreviated as AN) and engine speed.

[Problem that the invention seeks to solve]

However, with the above-mentioned conventional device, during engine transients, such as acceleration, there is a delay in A/N calculation processing, or the AFS detects the intake air amount of the engine to be lower than the actual amount, so the ignition timing is advanced more than the engine request. There was a problem in that it would shift to the side, causing knocking.

[Means for solving problems]

The ignition timing control device according to the present invention is provided with a smoothing means for smoothing the A/N ratio and a correction means for correcting the output of the smoothing means in accordance with the output of the throttle opening sensor.

[For production]

The smoothing means in this invention smoothes the A/N, and the correcting means further corrects this according to the throttle opening.

Although an A/N error occurs during engine transients, the i difference is corrected by the smoothing and correction described above, and optimal ignition timing control can be obtained.

〔Example〕

Embodiments of the present invention will now be described with reference to the drawings. “Figure 3 shows a model of the intake system of an internal combustion engine. 1 is the engine, which has a volume of 1 stroke, and is equipped with an AFS 13, which is a Karman vortex flowmeter, a throttle valve 12, a surge tank 11, and an intake pipe 15. Air is taken in through the engine, and fuel is supplied by the injector 14. Here, the volume from the throttle valve 12 to the engine 1 is assumed to be V. 16 is an exhaust pipe.

FIG. 4 shows the relationship between the intake air amount and the predetermined crank angle of the engine 1, (al is the predetermined crank angle of the engine 1 (hereinafter referred to as SGT). (bl is the amount of air passing through the AFS 13). Q., (e) is engine 1
The amount of air Q, , (dl indicates the output pulse f of AFS 13. Also, the period of rising of SGT from n-2 to n-1 times is t,, -1, from n-1 to n-th times. Let the rising period be t,1, and AFS1 in the period t.-4 and t.
Let the amount of intake air passing through 3 be Qs (n-11 and Q
,,,,,Period 1. -, and t. The amount of air that engine 1 takes in is Q1. Let n−□, and q, , , . Furthermore, periods t, , -1 and 1. The average pressure in the surge tank 11 and the average intake air temperature at the time of P and P and T and a (n-11s lnl
a fn-11 and T, L, 1. shall be. here,
For example, q, , -11 corresponds to the number of output pulses of the AFS 13 during tn-1. Also, since the rate of change in the intake air temperature is small, it is set as T yoT, and if the engine charging efficiency is constant, then P ・V=Q -R-T...
(1) m In-11c * (n-11s
tn+P −V=Q −R−T,,,, −
...12) Island (nl C@II'++. However, R is a constant. Then, the amount of air accumulated in the surge tank 11 and the intake pipe 15 during period 1 is Δ
If q, , , then ΔQ, ,, =Q, ,. ) Q@ (nl =V
a・[Tx(P-P)...
(3) The island 1nla+n-11 is obtained, and equations (1) to (3) are obtained. Therefore, engine 1 is running for a period t. The amount of air inhaled Q. , the amount of air passing through AFS13 Q1
It can be calculated using equation (4) based on o.

If ko and "C', vc = 0.51 SV, = 2.51, then Ql, ., = 0.83XQ, . -1, +0.
17XQ, I......(5).

Figure 1 shows the configuration of an engine ignition timing control device, 1
The AFS 13 outputs pulses as shown in Fig. 4(d) according to the amount of air taken into the engine 1, and controls the crankshaft. The angle sensor 17 responds to the rotation of the engine 1 as shown in FIG.
A pulse as shown in (for example, the crank angle is 180° from one pulse rise to the next rise) is output.

25 is an opening sensor that detects the opening of the throttle valve 12, and 20 is an AN detection means, which detects the number of output pulses of the AFS 13 that occur during a predetermined crank angle of the engine 1 based on the output of the AFS 13 and the output of the crank angle sensor 17. calculate,
Calculate the intake air amount A/N per predetermined crank angle. 21
is an AN calculation means including a smoothing means and a correction means, which performs calculations similar to equation (5) from the output of the AN detection means 20 and calculates the AFS 13 corresponding to the amount of air considered to be taken in by the engine 1. Calculate the number of pulses equivalent to the output.

That is, the A/N is smoothed, and then the opening sensor 2
Correction is performed according to the output of step 5. Further, the control means 22
Based on the output of the N calculation means 21, the output of the water temperature sensor 18 (for example, a thermistor) that detects the cooling water temperature of the engine 1, and the output of the crank angle sensor 17 that detects the rotation speed of the engine 1, it corresponds to the amount of air taken into the engine 1. The driving time of the injector 14 and the energization of the ignition coil 19 are controlled, thereby dividing the amount of fuel supplied to the engine 1. Further, the ignition coil 19 transmits its output voltage to the power distributor 2.
3 to the spark plug 24 for ignition.

Figure 2 shows a more specific configuration of the embodiment of B, and 30 is A.
FS 13, water temperature sensor 18 and crank angle sensor 1
7 is an input, and the four injectors 14 and ignition coils 19 provided for each cylinder of the engine are controlled by a differential control device.
It corresponds to the N detection means 20 to the control means 22, and the ROM 41.
A microcomputer with RAM42 (hereinafter referred to as c
Abbreviated as pu. ) 40. Also, 31 is A
The 2 frequency divider 32 connected to the output of the FS13 uses the output of the 2 frequency divider 31 as one input, and the other input terminal is connected to the CPU 4.
0, and its output terminal is connected to the counter 33 and the input P3 of the CPU 40. 34 is an ink face connected between the water temperature sensor 18 and the A/D converter 35, 36 is a waveform shaping circuit to which the output of the crank angle sensor 17 is input, and the output is sent to the interrupt input P4 of the CPU 40, the timer 47 and Input to counter 37. In addition, 38 is a timer connected to the interrupt power P5, and 39 is a voltage A of a battery (not shown).
An A/D converter that performs /D conversion and outputs it to the CPU 40,
43 is a timer provided between the CPU 40 and the driver 44, and is connected to the output cover of the driver 44 and each injector 14. Reference numeral 45 denotes an interface to which the output of the crank angle sensor 17 is input, and inputs a crank angle signal 11 to timers 46 and 47. The output of timer 47 is output from timer 46
and input to the reset terminal of DF/F48. or,
The output of the timer 46 is input to the set terminal of the DF/F 48, and the output of the DF/F 48 is input to the ignition coil 19 via the driver 49. Furthermore, timers 46 and 47
is inputted with the output of the CPU 40.

In addition, the output of the opening sensor 25 is connected to the interface 50 and A.
The signal is input to the CPU 40 via the /D converter 51.

Next, the operation of the above configuration will be explained. The output of the AFS 13 is divided by a frequency divider 31 and input to a counter 33 via an exclusive OR gate 32 controlled by the CPU 40. Counter 33 measures the period between falling edges of gate 32's output. The CPU 40 receives the falling edge of the gate 32 as an interrupt input P3, and performs interrupt processing every time the output pulse period of the AFS 13 or this frequency is divided by two.
Measure the period of the counter 33. The output of the water temperature sensor 18 is converted into a voltage by the interface 34, and converted into a digital value by the A/D converter 35 at predetermined time intervals, and is input into the CPU 40. The same applies to the output of the opening sensor 25. The output of the crank angle sensor 17 is transmitted via the waveform shaping circuit 36 to the CPU 40 interrupt manual input P4 and the timer 47.
and is input to the counter 37. The CPU 40 performs an interrupt process every time the crank angle sensor 17 rises, and detects the period between the rises of the crank angle sensor 17 from the output of the counter 37. The timer 38 generates an interrupt signal to the interrupt input P5 of the CPLJ 40 at predetermined intervals. The A/D converter 39 A/D converts the battery voltage (not shown), and the CPU
40 takes in this battery voltage data at predetermined time intervals. The timer 43 is preset in the CPU 40, and
0 output port P2 to output a predetermined pulse width, and this output drives the injector 14 via the driver 44. Further, the CPU 40 sets the energization angle To in the timer 46 and sets the ignition timing in the timer 47. The timers 46 and 47 count the 1° signal output from the crank angle sensor 17 as shown in FIG.
When it becomes 0, a signal is output to DF/F48. The timer 47 starts counting at the rise of the crank angle, and when it reaches 0, resets the DF/F 48 and cuts off the current of the ignition coil 19.

Timer 4G is activated when timer 47 reaches 0.
- Start down, and when it reaches 0, set D-F/F 48 and energize the ignition coil 19.

Next, the operation of the CPU 40 will be explained using flowcharts shown in FIG. 5 and FIGS. 7 to 9. First, Figure 5 shows the CPU 40
When a reset signal is input to the CPU 40, in step 100, the RAM 42,
Initialize the input/output boat, etc., convert the output of the water temperature sensor 18 to A/D in step 101, and store the W in the RAM 42.
Store as T. In step 102, the battery voltage is set to A.
/D conversion and stored in the RAM 42 as VB. In step 103, the period of the crank angle sensor 17 is 30/
T, is calculated, and the rotational speed N is calculated. Step 1
AN・N from the load data AN and rotation speed N, which will be described later in 04.
, /30 is calculated, and the output frequency F of AFS 13 is
Calculate. In step 1'05, the output frequency F.

Therefore, f is set for F as shown in FIG.

Then, calculate the basic driving time conversion coefficient K. In step 1'06, the conversion coefficient K is corrected using the water temperature data WT and stored in the RAM 42 as a driving time conversion coefficient. In step 107, the data is stored in the ROM in advance from the battery voltage data VB.
Mapping the data table f3 stored in 41,
The waste time T0 is calculated and stored in the RAM 42. In step 108, the energization angle T of the ignition coil 19 is determined at the rotational speed N. 1
．． Calculate l and step 109 teT'. , = 180
-Tol, l is calculated, and in step 110 T'' is set in the timer 46. After the process in step 110, the process in step 101 is repeated again.

FIG. 7 shows the interrupt processing for the output signal of the interrupt P3, that is, the output signal of the AFSI3. In step 201, the output TF of the counter 33 is detected and the counter 33 is cleared. This T
, is the period between the rises of the gate 32. Step 20
In step 2, the period T1 is determined by the output pulse period of the AFS 13 and stored in the RAM 42, and in step 203, the remaining pulse data P0 is added to the accumulated pulse data P to obtain new accumulated pulse data. This integrated pulse data is obtained by integrating the number of pulses of the AFS 13 output during the rise of the crank angle sensor 17, and is treated as 156 times one pulse of the AFSI 3 for convenience of processing.

In step 204, the remaining pulse data P is set to 156, and in step 205, Pl is inverted, and the interrupt processing is completed.

FIG. 8 shows the timer 38 in response to the output signal of the opening sensor 25.
Based on (shows interrupt processing every 10m5ec).

- In step 401, the output θ of the opening sensor 25 is A/D
In step 402, the deviation between the previous value and the current value is calculated and stored, and in step 403, the current value is stored in place of the previous value, and the interrupt processing ends.

FIG. 9 shows the CPU 40 using the output of the crank angle sensor 17.
The interrupt processing when an interrupt signal is generated in the interrupt input P4 is shown. In step 301, the period between the rises of the crank angle sensor 17 is read from the counter 37, stored in the RAM 42 as the period T8, and the counter 37 is cleared. If there is an output pulse of AFS 13 within the period T8 in step 302, then in step 303 the immediately preceding AFS 13
The time t of the output pulse. 1 and the current interrupt time t02 of the crank angle sensor 17, Δt=to2-t01 is calculated, and this is set as the period -.If there is no output pulse of the AFS 13 within the period T8, in step 304, the period T1.
Let l be the period -. In step 305, 156×′rs
By calculating /'rA, the time difference Δt is converted into output pulse data ΔP of the AFS 13. That is, the previous AFS 1
Pulse data ΔP is calculated assuming that the output pulse period of AFSI 3 and the current output pulse period of AFSI 3 are the same.

In step 306, if the pulse data ΔP is smaller than 156, the process goes to step 30B, and if it is larger, ΔP is clipped to 156 in step 307. In step 308, the pulse data ΔP is subtracted from the remaining pulse data P to obtain new remaining pulse data ΔP. In step 309, if the remaining pulse data P is positive, the process goes to step 313; otherwise, since the calculated value of the pulse data ΔP is too larger than the output pulse of the AFS 13, the pulse data ΔP is changed to P in step 310. , and the remaining pulse data is set to zero in step 312. In step 313, the pulse data ΔP is added to the integrated pulse data P8 to obtain new integrated pulse data P8. This data P8 corresponds to the number of pulses that the AFSI 3 is thought to have output during the current rise of the crank angle sensor 17. In step 314, calculations corresponding to equation (5) are performed. That is, the load data AN calculated up to the previous rise of the crank angle sensor 17
From the integrated pulse data PR, K, AN 10 (1-K
, JP, is calculated, and the result is set as the current new load data AN.

If the load data AN is larger than the predetermined value α in step 315, it is clipped to a in step 316 to prevent the load data AN from becoming too large than the actual value even when the engine 1 is fully opened.

In step 317, the integrated pulse data PFl is cleared. In step 318, the load data AN and drive time conversion coefficient are 0, and the wasted time T. From the driving time data T, =AN-
Then, +To is calculated, drive time data T is set in the timer 43 in step 319, and the timer 43 is triggered in step 320, so that four injectors 14 are simultaneously driven in accordance with the data T. In step 321, the rotation speed N is calculated from the above-mentioned L, and in step 322
Then, the above-mentioned Δθ multiplied by a constant is added to AN to obtain AN, and in step 323, AN is converted to β and β
Clip between 2. In step 324, AN, and N
1, the ignition timing A is stored in advance in the ROM 41.
Obtained by mapping from the data table f5 shown in the figure,
In step 323, this result is set in the timer 47, and the interrupt processing is completed.

FIG. 10 shows the timing when the frequency division flag is cleared in the processing of FIG. 5 and FIGS.
7 output is not shown and Dtc+ shows remaining pulse data 9,
It is set to 156 at each rise and fall of the frequency divider 31 (the rise of the output pulse of the AFS 13), and each rise of the angle sensor 17 is set to 156.
The calculation result is changed to 6 x T, /TA (this corresponds to the processing in steps 305 to 3]2). (d) shows a change in the integrated pulse data P6, and the remaining pulse data P is displayed each time the output of the frequency divider 31 rises or falls. (shows how it is integrated).

In the above embodiment, C, the output pulse of the AFS 13 during the rising edge of the crank angle sensor 17 was counted, but this may also be during the falling edge. You can count it. Further, although the output pulses of the AFS 13 are counted as a number, the number of output pulses multiplied by a constant corresponding to the output frequency of the AFS 13 may be counted.

〔Effect of the invention〕

As described above, according to the present invention, the intake air J2iA/N per intake of the engine is detected by the AN detection means, this Alx is smoothed by the smoothing means, and then corrected according to the output of the opening sensor. Accurate Alx is determined, and the ignition timing is controlled based on this Alx and the engine rotational speed, so that the ignition timing can be controlled accurately.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the ignition timing control device B according to the present invention, FIG. 2 is a block diagram showing a specific example of the ignition timing control device for the internal combustion engine, and FIG. 3 is a block diagram of the ignition timing control device B according to the present invention. A configuration diagram showing a model of the intake system of a related internal combustion engine, FIG. 4 is a diagram showing the relationship between the crank angle and the air intake system, and FIGS. 5 and 7 to 9 show an embodiment of the present invention. Flowchart 1, which shows the operation of the ignition timing control device for an internal combustion engine according to FIG. Timing chart showing timing chart, 11th
The figure is a timing chart showing the on/off operation of the ignition coil, and FIG. 12 is an ignition timing map stored in the ROM. 1 - Niresin, 12 - Throttle valve, 13 Air flow sensor (Karman Pi'tQ tester), 1s intake pipe, 17... Crank angle sensor, 19 Ignition coil,
20..AN detection means, 21..AN calculation means, 22..
- Control means, 25 opening sensor. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] (1) An intake air amount detection means that is arranged upstream of the throttle valve and detects the intake air amount of the engine, an engine rotation speed detection means that detects the engine rotation speed, and detects the opening degree of the throttle valve that adjusts the engine intake air amount. AN opening sensor that detects the output of the intake air amount detection means between predetermined engine crank angles, smoothing means that smoothes the output of the AN detection means, and converts the output of the smoothing means into the output of the opening sensor. An ignition timing control device comprising a correction means for correcting the ignition timing accordingly, a control means for controlling the ignition timing of the engine based on the output of the engine rotation speed detection means and the correction means.