JPS63280855A - 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 installing a means which corrects 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. CONSTITUTION:A Karman's vortex type air flow sensor 13 outputs pulse signals according to the air quantity inhaled into an engine 1, and a crank angle sensor 17 outputs pulse signals according to 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. An opening degree sensor 24 detects the opening degree of a throttle valve 12, and a correcting means 25 corrects the output of the A/N detecting means 20 according to the output of the opening degree sensor 24. A control means 21 controls an injector 14 and an ignition coil 19 according to the output of the correcting 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 adjusting the ignition timing of an internal combustion engine, an intake air flow sensor (hereinafter abbreviated as AFS) is placed upstream of the throttle valve, and the intake air mA/N per intake of the engine calculated from the output of the AFS is calculated from the output of the AFS. The ignition timing of an internal combustion engine is controlled based on the engine speed (also abbreviated as AN) and the 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 is a problem with it shifting to the side and causing knocking.

[Means for solving problems]

The ignition timing control device according to the present invention is provided with a correction means for correcting the output of the AN detection means for detecting A/N based on the output of the throttle opening sensor.

[For production]

The correction means in this invention corrects the output of the AN detection means, which causes an error during engine transients, based on the output of the throttle opening sensor, thereby optimizing the ignition timing.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. 1st
The figure shows the configuration of an engine ignition timing control device, in which 1 is the engine, 10 is an air cleaner disposed upstream of the AFS 13, 11 is a surge tank, 12 is a throttle valve, 13 is a Karman vortex type AFS, 14 15 is an injector, 15 is an intake pipe, and 16 is an exhaust pipe. AFS13 outputs a pulse according to the amount of air taken into engine 1,
The crank angle sensor 17 outputs a pulse (for example, the crank angle is 180° from one pulse rise to the next rise) in accordance with the rotation of the engine 1. 20 is an AN detection means, which detects whether the AF is between 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.
Count the number of output pulses in S13. The opening sensor 24 detects the opening of the throttle valve 12, and the correction means 25 corrects the output of the AN detection means 20 according to the output of the opening sensor 24. The control means 21 uses the output of the correction means 25, the output of the water temperature sensor 18 (for example, a thermistor) that detects the wetness of the cooling water of the engine 1, and the output of the crank angle sensor 17 that detects the rotation speed of the engine 1 to determine whether the engine 1 is inhaling. The driving time of the injector 14 and the energization of the ignition coil 19 are controlled in accordance with the amount of air, thereby controlling the amount of fuel supplied to the engine 1. Further, the ignition coil 19 supplies its output voltage to the ignition plug 23 via the power distributor 22 to perform ignition.

FIG. 2 shows a more specific configuration of this embodiment, and 30 is A.
FS 13, water temperature sensor 18 and crank angle sensor 1
7 is a control device that controls the four injectors 14 and ignition coils 19 provided for each cylinder of the engine, and this dividing device 30 is similar to A in FIG.
This corresponds to the N detection means 20, the correction means 25, and the control means 21, and is realized by a microcomputer (hereinafter abbreviated as CPU) 40 having a ROM 41 and a RAM 42. Further, 311 is a 2-frequency divider connected to the output of the AFS 13, and 32 is an exclusive OR gate with the output of the 2-frequency divider 31 as one input and the other input terminal connected to the input P1 of the ecPU 40. Its output terminals are counter 33 and CP
Connected to input P3 of U40. 34 is the water temperature sensor 18
36 is a waveform shaping circuit connected between the interface and the A/D converter 35, into which the output of the crank angle sensor 17 is input, and the output is input to the interrupt input P4 of the CPtJ40.
, is input to the timer 47 and counter 37. Also, 3
8 is a timer connected to the interrupt input P5; 39 is an A/D converter that A/D converts the voltage of a battery (not shown) and outputs it to the CPU 40; 43 is the CPU 40 and a driver 44;
The output of the driver 44 is connected to each injector 14 by a timer provided between the two. Reference numeral 45 denotes an interface to which the output of the crank angle sensor 17 is input, and inputs a 1 degree signal of the crank angle to timers 46 and 47. timer 4
The output of 7 is input to the reset terminal of the timer 46 and DF/F 48. Also, the output of the timer 46 is D-F/F4.
8 and is input to the ignition coil 19 via the output capacitor driver 49 of the D-F/F 48. Furthermore, timers 46 and 47 are inputted with the output of CPtJ40. In addition, the output of the opening sensor 24 is connected to the interface 50.
and is input to the CPU 40 via the A/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 inputted 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 falling edge of the gate 32 is input to the CPU 40 as an interrupt input P3, and the CPU 40 performs an interrupt process every time the output pulse period of the AFS 13 or this frequency is divided by two, and measures the period of the counter 33. The output of the water temperature sensor 18 is converted into a voltage by the interface 34, converted into a digital value by the A/D converter 35 at predetermined time intervals, and is input to the CPU 40. The same applies to the output of the opening sensor 24. The output of the crank angle sensor 17 is inputted to the interrupt input P4 of the CPU 40, the timer 47, and the counter 37 via the waveform shaping circuit 36. 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 P5 of the CPU 40 at predetermined intervals. A/D converter 39
A/D converts the battery voltage (not shown), and the CPU 40
captures this battery voltage data at predetermined intervals. The timer 43 is preset in the CPU 40 and is triggered by the output port P2 of the CPU 40 to output a predetermined pulse width, and this output is sent to the injector 14 via the driver 44.
to drive. Further, the CPU 40 sets the energization angle T in the timer 46 and sets the ignition timing in the timer 47. As shown in FIG. 9, the timers 46 and 47 count the 1 degree signal output from the crank angle sensor 17, and output a signal to the DF/F 48 when the count reaches 0. The timer 47 starts counting at the rise of the crank angle, and when it reaches 0, D-
The F/F 48 is recessed and the current of the ignition coil 19 is turned off. The timer 46 starts the timer 47 goes from 1 to down, and when it reaches 0, it goes D-F.
'/F482 Sesotoshi, energize the ignition coil 19.

Next, the operation of the CPLJ 40 will be explained using flowcharts I. of FIG. 3 and FIGS. 5 to 7. First, Figure 3 shows CP
The main program of the IJ 40 is shown, and when the reset number is input to the CPU 40, the RA is
M42, input/output boat, etc. are initialized, and in step 101, the output of the water temperature sensor 18 is A/D converted, and the ltA
As WT in M42, I made 3 rounds. In step 102, the battery voltage is converted to A/[) and stored in the RAM 42 as VB. In step 103, the crank angle sensor 17
30/T is calculated from the period T8, and the rotation speed N is calculated. In step 104, the load data AN and rotation speed N, y) JAN・N, /30, which will be described later, are calculated, and the AFS
13 output frequency F, is calculated. In step 105, the output frequency F.

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

Calculate the basic driving time conversion coefficient. Step 10
At step 6, the conversion coefficient 1 (corrected by the water temperature data WT) is stored in the RAM 42 as a driving time conversion coefficient.
pine pig the data table E3 stored in 41,
The wasted time ' 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.

, and in step 109 T'o, = 180-T
Calculate o, and send T'l to timer 46 at ST2/110.
, set ヮ. After the process in step 110, the process in step 101 is repeated again.

FIG. 5 shows the interrupt processing for the output signal of the interrupt P3, that is, the AFS 13. In step 201, the counter 33
The output TF of is detected and the counter 33 is cleared. This T- is the period between the rises of the gate 32. Step 2
In step 02, the period T is stored in the RAM 42 as the output pulse period - of the AFS 13, and in step 203, the remaining pulse data P0 is added to the integrated pulse data P9, and the result is set as new integrated pulse data PFl. This integrated pulse data P
R is the AF output during the rise of the crank angle sensor 17
This is to integrate the number of pulses of S13, and AFS 13
For convenience of processing, one pulse is multiplied by 156.

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. 6 shows the timer 38 in response to the output signal of the opening sensor 24.
Based on (shows interrupt processing every 10 msec. Step 40
In step 1, the output θ of the opening sensor 24 is A/D converted, and 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 replaced with the previous value. Store and end interrupt processing.

FIG. 7 shows that the CPU
4.0 shows the interrupt processing when an interrupt equal sign occurs in the interrupt P4. In step 301, the crank angle sensor 17
The period between the rising edges of T is read from the counter 37, and the period T
8 in the RAM 42, and the counter 37 is cleared. In step 302, if there is an output pulse of AFS 13 within the period T8, in step 303, the immediately preceding AF
Time difference Δt between the time t01 of the output pulse of S13 and the current interrupt time t02 of the crank angle sensor 17 = t02
'01 is calculated and this is set as the period T9. If there is no output pulse of AFS 13 within period T9, step 30
4, the period T8 is defined as the period T. 1 in step 305
From the calculation of 56 x TS/TA, the time difference ΔT is AFS 1
It is converted into output pulse data ΔP of 3. That is, the previous A
The pulse data ΔP is calculated assuming that the output pulse period of the FS 13 and the current output pulse period of the AFS 13 are the same. In step 306, if the pulse data ΔP is smaller than 156, the process goes to step 308; if it is larger, the process goes to step 30.
7 clips ΔP to 156. In step 308, the pulse data ΔP is subtracted from the remaining pulse data P to obtain new remaining pulse data P. shall be. In step 309, the remaining pulse data P. If is positive, go to step 312;
In other cases, the calculated value of pulse data ΔP is AFS 13
The pulse data ΔP is set to P in step 310. Same as 1. In step 311, the remaining pulse data is set to zero. In step 312 &
! The pulse data ΔPG is added to the calculated pulse data P to calculate the number of pulses A/N that are considered to have been output by the AFSi3 during the current rise of the crank angle sensor 17.

In step 313, the load data AN and drive time conversion coefficient are set to 1, and the waste time T is set. Drive time data T, = A
+To is calculated for N-, drive time data T is set in the timer 43 in step 314, and step 315
By triggering the timer 43 at T, four injectors 14 are simultaneously driven in accordance with data T. In step 316, the rotation speed N is calculated from the crank angle period T8, in step 317, the product of the aforementioned Δθ multiplied by a constant is added to AN to obtain AN, and in step 318
Clip N between β and β. In step 319, A
The ignition timing A is determined from NB and Nll by mapping from the data table f shown in FIG. 10 previously stored in the ROM 41, and in step 320, this result is set in the timer 47, and the interrupt processing is completed.

FIG. 8 shows the timing command when clearing the branch flag in the processing of FIG. 3 and FIGS. 1
The output of 7 is shown. (C) (indicates the remaining pulse data P, rising and falling of the frequency divider 31)) (rising of the output pulse of AFS] 3) is set to 156, and every rising of the crank angle sensor 17, for example, P is set to 156. . , = Po-156
It is changed to the calculation result of XT, /TA.

[dl is! It shows the change in the A calculation pulse data P8, and the remaining pulse data P is displayed every time the output of the frequency divider 31 rises or falls. It shows how is accumulated.

FIG. 11 shows the operating waveforms of each parameter during engine transients. For example, during acceleration, the throttle opening increases, the boost pressure (intake pipe pressure) also increases, and the output deviation of the opening sensor 24 ( rate of change) also increases, and the A/N
also becomes larger. However, due to the calculation delay and the detection error of the AFS 13, the value is determined to be smaller than the value at 'A' shown by the dotted line. Therefore, the ignition timing shifts to the advance side, but in this example, Δθ is multiplied by It becomes appropriate.In addition, when decelerating, △θ
becomes negative, and AN is also correct as shown by the dotted line. In addition, since Δθ=0 in cases other than transient, the AN is not corrected.

In the above embodiment, the output pulses of the AFS 13 during the rising edge of the crank angle sensor 17 are counted, but this may also be during the falling edge, or the number of output pulses of the AFS 13 during several cycles of the crank angle sensor 17 is counted. It's okay. or,
Although the output pulses of the AFS 13 are counted, the number of output pulses multiplied by a constant corresponding to the output frequency of the A'FS 13 may be counted.

[Effects of the Invention] As described above, according to the present invention, the intake gAN per intake air is determined to be deviated from the actual value during transitions such as acceleration and deceleration of the engine, and this is detected by the throttle opening sensor. The engine's ignition timing is corrected according to changes in the engine's output, making it possible to accurately control the engine's ignition timing even during transient conditions.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an ignition timing control device according to the present invention, FIG. 2 is a block diagram showing a specific embodiment of the ignition timing control device for the internal combustion engine, and FIG. 5 to 7 are flowcharts showing the operation of the ignition timing control device for an internal combustion engine according to an embodiment of the present invention, FIG. 4 is a diagram showing the relationship between the basic drive time conversion coefficient and the AFS output frequency, and FIG. 8 is a timing chart showing the flow timing of Figs. 5 to 7, Fig. 9 is a timing chart showing the on/off operation of the ignition coil, and Fig. 10 is a ROM
The ignition timing map stored in FIG. 11 is an operating waveform diagram of each variable make during engine transient. 1. Engine, 12. Throttle valve, 13' air flow sensor (Karman eddy current fi meter), 1s intake pipe,
17... Crank angle sensor, 19. Ignition coil, 20
... AN detection means, 21.. Control means, 24. Opening degree sensor, 25.. Correction means. Note that the same reference numerals in the figures indicate the same or corresponding parts. Figure 1 24 Seki Pltn Ding

Claims (1)

[Claims] (1) Karman vortex type intake air amount detection means for detecting the intake air amount of the engine, engine rotation speed detection means for detecting the engine rotation speed, an opening sensor that detects the opening degree of the throttle valve that adjusts the engine intake air amount; AN detecting means for counting the output of the intake air amount detecting means between predetermined crank angles, a correcting means for correcting the output of the AN detecting means according to the output of the opening sensor, and an output of the engine rotation speed detecting means and the correcting means. An ignition timing control device comprising a control means for controlling ignition timing of an engine.