JPS601375A - Ignition timing control method for internal-combustion engine - Google Patents

Abstract

PURPOSE:To prevent ignition timing from being out of MBT by stopping feedback control to the MBT when a prescribed torque change is produced in the captioned method wherein the ignition timing is periodically changed and fedback for control to a minimum lead angle for obtaining the maximum torque. CONSTITUTION:In operation of an engine, a base lead angle value is estimated in an ignition setting circuit 21 based on suction pipe negative pressure PB and the number N of engine revolutions obtained from an intake air pressure sensor 14 and a turning angle sensor 7 respectively, and optimum ignition timing control is performed for leading and delaying the ignition timing at every four firing, i.e., at every two revolutions of the engine. And, torque Tn is measured from the output of a torque sensor 16 at every period for which the turning angle is alternately led or delayed, and the variation value DELTAT of the torque is estimated from a formula: DELTAT=(Tn+2+Tn)-(2.Tn+1). Then, this variation value DELTAT is compared with a set value to perform control to optimum ignition timing, and at this time feedback control to MBT is stopped in case the amount of torque changes is larger than a certain set value.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention improves the ignition timing of internal combustion feedback by Milimum 5pa.
rkadvance for Be5t Touque
This invention relates to a control method for controlling ('Jl+) (minimum advance angle for obtaining il large torque) (hereinafter referred to as MBT).

Conventionally, as a method of controlling the ignition timing to MBT, a method such as that disclosed in Japanese Patent Application Laid-Open No. 56-34959 is known.

However, when controlling the ignition timing of the internal combustion engine (hereinafter referred to as the engine) using MBT, if a torque change occurs that originates from the drive power transmission system (for example, the clutch in a car with a manual transmission) (intermittent and resulting gear changes, gear changes in automatic transmission vehicles, changes in road load due to uneven road surfaces, etc.), these disturbances make it impossible to perform MBT control accurately.
There was a problem that the ignition timing was off from the MBT.

The present invention has been made in view of the above problems, and when a torque change originating from the driving force transmission system as described above occurs, MBT control is stopped during this period and the ignition timing is changed to MBT.
The purpose of this is to prevent deviations from occurring.

The present invention will be explained below with reference to Examples.

In FIG. 1, an engine 1 is a well-known 4-cylinder 4-stroke spark ignition engine, which inhales the air-fuel mixture generated by vaporization Fiv2 through an intake manifold 3, and a spark plug (not shown) connects an ignition coil 4 to a distributor 5. ■Voltage is applied through.

A ring gear 6 that rotates in synchronization with the crankshaft of the engine 1 is provided with a rotation angle sensor 7 and a dead angle sensor 8, each of which is an electromagnetic detector, facing each other. In the rotation angle sensor 7, the number of teeth 6a of the ring gear 6 is 11541.
If it is 1, the engine speed is 600rprn (=10
rps), a pulse signal with a frequency of 115011z is output. The angle sensor 8 is the first one in the ring gear 6.
It is provided opposite to the reference position peak 6b' formed at a position 100 degrees before the top dead center of the cylinder, and outputs a JJ=tits pulse signal at 100 degrees before the top dead center of the first cylinder. .

The waveform shaping circuits 10 and 11 are well-known circuits that amplify the output signals of the rotation angle sensor 7 and the reference angle sensor 8, respectively, and shape them into square waves. The set number circuit 12 receives the output pulse of the waveform shaping circuit 11 and the clock pulse C+ of the clock circuit 13.
It calculates the engine speed by 61 from , and outputs the output in binary code.

Although the details of this stitch count circuit 12 are not shown, the gate is opened by the output pulse of the waveform shaping circuit 11, and the clock pulse CI from the clock circuit 13 is passed through the NAND circuit.
gate, a counter that coefficients the clock pulse that has passed through this NAND gate, a latch circuit (temporary storage circuit) that temporarily stores the i1 value of this counter and determines the rotation speed using a binary code, and the output of the waveform shaping circuit 11 It consists of a signal generator that generates a recent signal for the counter and a storage command signal for the latch circuit by means of pulses.

The clock circuit 13 is composed of a known square wave oscillation circuit, a frequency dividing circuit that divides the frequency of the square wave of this oscillation circuit, a waveform shaping circuit that converts the output of the frequency dividing circuit into a pulse with a very small pulse width, and a supply circuit. It outputs clock pulses C1 to C5, which serve as reference time signals, to each block such as the counting circuit 12.

The pressure sensor 14 is of a known semiconductor type, and detects the intake pressure in the intake manifold 3 of the engine 1 and outputs an output in the form of an analog voltage. The intake pressure in the intake manifold 3 corresponds to i+M of the engine 1, and when the rotation speed of the engine 1 is the same, when the load is small, the intake pressure is small, and when the load is large, the intake pressure is high. Therefore, the pressure sensor 14 detects the load of the engine 1, and serves as a load sensor.

The A-D converter 15 converts the analog voltage of the pressure sensor 14 into digital.

The torque sensor 1G is coupled between the ring gear 6 of the engine 1 and the clutch, and an elastic body is provided between the first shaft on the driving side of the engine 1 and the second shaft on the 71 movement example of the clutch.
The torque is increased by the relative displacement stitch in the circumferential direction between the two shafts due to the deflection of this elastic body.

FIG. 2 is a cross-sectional view of the torque sensor 16&)t[(cross-sectional view) according to the present invention, and FIG.
1 is a shaft body on the drive side that is rotationally driven by the engine 1;
162 is a shaft body on the driven side that is supplied to the load (clutch). The shaft 162 side of the shaft 161 on the driving side has a plurality of elastic body receiving portions 161a provided at equal angular intervals (for example, four at every 90°). - A plurality of elastic body receiving portions 162a are provided at one end of the shaft body 161 side of the shaft body 162 on the force relief driving side so as to face the elastic body receiving portions 161a. And elastic body receiving parts 161a & 162a
Four elastic bodies 164 with elastic body receiving parts 16'3a and 163b attached on both sides are inserted between the two, and the elastic bodies 164 are inserted into one end of the shaft body 161 by the coupling flange 165, and the rivet 173 Fixed by Here, the elastic body 164 uses a coil spring. Moreover, 160 is a cylindrical stator arranged on the outer peripheral side of the shaft bodies 161 and 162, and is fixed so as not to be fixed by bearings 169 and 170, respectively.

For example, electromagnetic pickups 171 and 172 are mounted opposite to the rotating bodies 166 and 167, respectively, and the electric signals detected by the pisocqua knobs 171 and 172 are sent to the outside via lead cotton 171a and 172a. You will be guided by the circuit.)

In the above configuration, when the shaft body 161 rotates in the direction of the arrow shown in FIG.
61a presses the elastic body receiving portion 162a via the elastic body 164, and as a result, the shaft body 162 and the shaft body 161
Rotates in the same direction as 61. When the load on the shaft body 162 is small, the deflection of the elastic body 164 is small, but as the load increases, the deflection of the elastic body 164 increases in relation to the load.

Therefore, the rotating bodies 166 and 167 respectively connected to the shaft bodies 161 and 162 rotate at the same speed and in the same direction, but when the load on the shaft body 162 increases, the elastic body 164 bends.
The rotating body 167 lags behind the rotating body 166, and its relative position in the circumferential direction changes.

At this time, the relative change amount of the rotating bodies 166 and 167 is related to the deflection of the elastic body, that is, the torque of the load.

FIG. 4 is a waveform diagram when processing pink-up 171.172 electrical signals. +a) is pickup 171
The pulse waveform of the electric signal output from the pickup 172 (bl is the pulse waveform of the electric signal output from the pickup 172. When a load is applied, the phase of the electric signal output from the pickup 172 is delayed according to the load torque. .(a
) and (bl), a load torque signal as shown in (C) is obtained. In this signal, the pulse repetition period T is determined by the constant rotation speed of the shafts 161 and 162. However, the time width t of the pulse is +
It is related to the phase difference between the al signal and the (bl signal, that is, the load torque.

The angle signal circuit 17 uses the output pulse of the waveform shaping circuit 1O111 to determine the B 'I' D C10 of each cylinder of the engine l.
Outputs a 0° position signal (Rl 00.).

The phase difference counting circuit 20 outputs the angular phase difference due to the deflection between the first shaft 161 and the second shaft 162 of the torque sensor 16 as a digital quantity to the ignition setting circuit 21.

The ignition setting circuit 21 is composed of a plurality of ICs or microcomputers, and includes a digital signal indicating the engine rotation speed of the 61 number circuit 12, a clock pulse C2 of the clock circuit 13, and a manifold 3 of the 8-D converter 15. Digital signal based on intake pressure, phase difference counting times 11 &
A digital signal corresponding to the torque fluctuation of 20 and an angle signal of the angle signal circuit 17 are input. Then, a dither θd is applied to the base advance angle θB determined from the rotational speed and the intake pipe negative pressure, and the advance and retard angle are alternately performed every certain period, and the torque Tn during that period is measured. Each T n obtained in this way is (11
The torque fluctuation value ΔT is calculated using the formula.

ΔT = ('r' n + 2 + i″n) (2
・Tn + + ) - (1) By determining the order of positive and negative signs of the torque fluctuation value ΔT obtained using formula (1) and the magnitude of the set value, advance or retard the correction angle Δθ with respect to the base advance angle θB. Set the feedper to the MBT by turning it at an angle or holding the angle.
2 control.

Further, the setting circuit 21 is set to the BTDCloooo of the engine 1.
The above lead angle value based on
Divide the advance angle value from the standard by 3.13 degrees (= 360 degrees / 1'1.5), which is the angle for each peak 6a of the ring gear 6, and use this division value as the first output value''. 2nd output value,
° and LT-tF″5 1st (7): J7′f lator 22
, -ffi2 to the comparator 23 in binary code. Here, if the retard value is, for example, 40 degrees, then 4
0°=12x3. x, ao, 0.77...°, but the first output value m is 01 representing 12 in binary code.
100, and the second output value n is the remainder angle 0.77
... It is expressed as a number obtained by dividing ° by the engine rotation speed, converting it into time, and converting it into a binary code.

The comparators 22 and 23 are circuits that compare the value calculated by the ignition setting circuit 21 and the actual crank angle of the engine 1, and output an output signal when the two match digitally. It is reset by the reference angle signals R(0) and R(18Q) of the signal circuit 17, and then the comparison is started and the first output value of the outputs of the ignition angle setting circuit 21, for example, 5-bit data m
When the number of output pulses from the waveform shaping circuit 10 matches, an output signal is output and the second comparator 23 is reset. Then, from this point on, the second comparator 23 starts comparing, and when the number of pulses of the clock pulse C4 of the clock circuit 13 matches the second output of the output of the ignition angle setting circuit 21, for example, 10-bit data n, it outputs a signal. issue. This output signal becomes an ignition timing signal.

The energizing circuit 24 controls the ignition coil 4 based on the output signal of the second comparator 23 and the angle signal R100 of the angle signal circuit 17.
This is a circuit that determines the time to energize and ignites, and the Eve knife 25 is a known ignition circuit that amplifies the power of the output signal of the energization circuit 24 to operate the ignition coil 4.

Next, the ignition setting circuit 21, which constitutes the main part of the present invention, will be explained. This ignition setting circuit 21 uses a microcomputer. Regarding the configuration operations of the microcomputer, a description thereof will be omitted here, and only the details of the control calculations will be described.

Flowchart 1 of the program regarding the contents of control calculations of the microcomputer will be explained with reference to FIGS. 5 and 9.

FIG. 5 shows the calculation of the ignition timing at °C, and FIG. 6 shows the processing regarding the torque drop.

First, ignition timing calculation will be explained using flowchart 1 in FIG. Step 300 is the start point i for calculating the ignition timing, and 180
This is performed by interrupt calculation according to the 15th degree of the °GA cycle. Therefore, each time the 180'aΔ period signal arrives, the microcomputer uses this as a trigger to perform the main interrupt calculation.

In step 301, the contents of the register immediately before the interrupt occurs are temporarily stored in the memory, and the calculation starts from the next step. Step 302 reads the intake pipe negative pressure Ps digitized by the AD converter 15. Step 3
03 calculates the engine rotation speed N from the engine rotation period counted by the counting circuit 12. Step 304 calculates the base advance angle MBESA from the PB and N thus obtained. As shown in FIG. 7, the base advance angle for each condition of N and PB is predetermined ζ, so this can be calculated by two-dimensional Ti1f l1il /iri. In step 305, the ignition number counter Nl is incremented by 1, and in step 30G, it is compared with 4. This controls the optimum ignition timing: i! i calculation is 4 ignitions, i.e. edge 22
This is because it is performed every rotation. If step 306 is No, jump to step 309, and if YES, set counter Nl to 0 in step 307, and in step 308 set a retard flag for optimal ignition timing detection (hereinafter referred to as dither flag) fDiZ (7). In other words, the ignition timing is advanced or retarded every 4 ignitions and every 22 revolutions of the edge to control the ignition timing. Figure 8 shows the time chart (al is the base advance). This shows that the angle MBESA is corrected by α° every four ignitions, and (bl is the ignition timing of (al) that is alternately advanced and retarded by an angle of MDiZ (C1 As shown, a slight increase/decrease in torque is caused, this is detected, and the optimal ignition is controlled to 1-1 by the calculation described below.

Step 309 checks counter NI=1, and if No, jumps to Step 314, and if YES, goes to Step 310 to flag fsiG to indicate completion of torque value addition.
Set the dither flag f on Ste Knob 311.
Check DiZ, and if it is “l”, advance the base advance angle MBESA by MDiZ in step 312 and 0”
If so, in step 313 the angle is retarded by MDiZ. This achieves the ignition shown in FIG. 8(b).

Step 314 checks the MBT control execution flag fEB, and if it is 1'', i.e., executable, executes MBT control from step 315, and if O'', i.e., cannot be executed, jumps to step 320, and cancels M13'r control. and holds the previous value. The flag fl"B will be explained later in the flowchart of FIG.
If so, calculations for °ζ optimum ignition timing control are performed in steps 316-329.

In step 361, the average torque value T n s 'rn +1 of the four ignition periods obtained from the flowchart of FIG.
Calculate the torque fluctuation value ΔT from % T 'n + 2 using the +11th formula. The thus obtained ΔT is the set value MTS
The ignition timing is controlled to the optimum ignition timing.

The determination method is to advance, bold, or retard the ignition timing in eight ways shown in the table of FIG.

If we explain the table of Fig. 9 using the graph of Fig. 1θ,
FIG. 0 is a graph showing the relationship between the engine generated torque 'I' and the ignition timing θ. When the ignition timing is advanced or retarded in the region 1 in Figure 10, which is on the retarded side than the optimum ignition timing θ0, any of the results 1, 2.5.6 in the table in Figure 9 will be obtained. , when the ignition timing is advanced or retarded in the 10th recess area, any of the results in 3.4.7.8 of the table in FIG. 9 is obtained. Steps 317, 318, 319, 320, 321, and 326 determine the advance angle and advance angle.
．． It is 327.328. Then, the advance angle, the advance angle flag fESA is set to l'', "'0" is set] and the hold flag flOL is set to "1", and the hold flag is set to '0'.

Step 322 checks the flag f ESA, step 323 calculates an advance angle, and step 324 calculates a retard angle. Step 325 is step 312.
5EXEC, which is the result of calculating the optimum ignition timing added to the ignition timing obtained in step 313, becomes the actual executed ignition timing. Step 329 is when the ignition timing is held, and step 31
2. Based on the results of 313 and the MBT control results up to the previous time, the following steps were taken. Step 330 is the execution ignition timing value 5EXEC.
is output separately into 4f(m) of the first comparator river and n of the second comparator river, and the (-) signal is output from the comparator for ignition at a predetermined ignition timing.This completes the ignition timing interrupt. Since the calculation is completed, step 331
At step 332, the register is returned to the value before the ;51J interrupt occurred, and at step 332, the process returns to the original state.

Next, in flowchart 1 of FIG. 6, the torque continuation calculation will be explained. Step 351 is the starting point of the torque continuation calculation, and is started at the rising edge of the bl signal (see FIG. 4).Step 352 temporarily stores the contents of the register in the memory, and step 353 4 (C1 phase difference data counted in FIG. N2 is the number of operations.

In step 35G, the ignition timing is advanced or retarded every four ignitions and the "C" flag is checked. If YES, step 357 is performed to check the previous average torque value Tn,
++ by Tn=SiG+N2, respectively. In this way, the three torque value data used in step 316 of the flowchart of FIG. 5, Tns 'l'n + 1
, 'I'n + 2 are obtained.

Step 358 calculates the new average (Ii') from the next interrupt) and ijj calculation, so the memory S
Clear iG and counter N2.

In step 359, the torque value Tn is set.
If it is smaller than B, the stethoscope 361 is 1.ri (aTn
If the absolute value of the difference between and the previous torque value Tn+ is larger than the set value C, under one of the above three conditions, step 362 jumps and the MBT control execution flag fFB is set to "0".
”, and in other cases, the flag fFB is set to “l”.
shall be. To explain this part in more detail using the example of FIG. 11, the set values A and B in the figure are the range of torque generated by the engine, where A is a large value of 1, and B is a minimum value of 0. Here, due to the vibration of the drive system that connects the clutch at time 1o, the torque value T n may exceed the setting (aA), and the change in torque value ii I T n +
-'l'nl becomes very large and becomes larger than the upper limit value C of the amount of change during normal driving.In addition, steps 359 and 360. 361 is established.In this way, in steps 359 to 363, M B T
Determine whether control should be performed.

Step 364 returns the register to the value before the interrupt occurred, and step 365 returns to the original value.

The construction diagram described above and its operation will be explained. In FIG. 1, the rotation angle signal obtained from the rotation angle sensor 7 and the crystalline angle sensor 8, data on the position and engine speed, and the intake pipe negative pressure indicating the engine load state obtained from the pressure sensor 14. The ignition setting circuit 21 calculates a predetermined ignition timing from the data. Furthermore, the ignition timing is alternately advanced by a predetermined angle with respect to the two ignition timings.
The engine 1 is retarded to generate a slight change in l·lux. This slight change in torque is detected by the torque sensor 16 and read as a phase difference by the counting circuit 20 into the ignition setting circuit 21, where it is converted into a torque value and then the ri
tx + formula Δ'I"= (T n + 24- T n
) −(2・T n + + )′C torque fluctuation trend Δ
Put on the T.

The torque fluctuation value Δ′1゛ obtained in this way is the set value MTS
In comparison with the table in FIG. 9, control is performed to the optimum ignition timing.

However, if the obtained torque value T n is larger than a certain setting value A or smaller than a certain setting value B,
If the amount of change is greater than a certain setting 4fLC, and at least one of the above three conditions is satisfied, MBT control is stopped and previous values other than the base advance angle value are bolded.

Next, a second embodiment of the present invention will be described. In the first embodiment, torque changes originating from the driving force transmission system were directly detected by a torque sensor, but in this embodiment, a clutch switch that detects engagement and disengagement of the clutch and a change in the transmission 3M! (
For example, a change in torque is indirectly detected by a shift sensor that detects a change in the shift position, and MBT control is stopped.

This will be explained in flowchart 1 of FIGS. 12 and 13. Steps 371 to 3 of the 12th Interval IJ-Chart
78 is steps 351 to 358 of the flowchart in FIG.
It is the same as that, and the torque 41'f'I' is read. t'fs l Flowchart 1 in Figure 3 detects clutch disengagement and gear change and then sets an execution flag (FB is set to "o". First step 3) to stop MBT control for a certain period of time. It is started at each starting point. Step 382 temporarily stores the contents of the register in memory. Steps 383 and 384 check clutch engagement and gear change, and if YES, step 385 sets the flag f F 13-0 to MBT.
Control is canceled. Steps 386, 387, 388,
389 is a routine for keeping rFB=0 for a certain period of time after the clutch is engaged or the gear change is stopped.

Step 390 returns the register to the value before the interrupt occurred, and step 391 returns to the original value.

As explained in FIG. 11, the reason why the MBTili control is stopped by setting fFB=0 for a certain period of time after the clutch engages or shifts occurs is when the clutch engages or shifts at time 1o. For a certain period of time T +-+ o c. Between o! ! 1. This is because vibration is occurring in the power transmission system, and steps 386 to 389 Lt of the free chart in FIG.
Making HOLD.

As explained above, in the present invention, M13T control is suspended for a certain period of time after torque fluctuations are generated from the drive power transmission system such as clutch disengagement or gear change. This has the excellent effect of solving the problem that the ignition timing of the engine ignition timing deviates from the MBT due to intermittent operation, speed change, and fluctuations in speed from the drive system.

[Brief explanation of the drawing]

Fig. 1 is an overall configuration diagram showing one embodiment of the present invention, Fig. 2 is a partial sectional view of the torque sensor in Fig. 1, Fig. 3 is a sectional view taken along line 8-A in Fig. 2, and Fig. 4 is a waveform diagram showing the torque sensor signal, Figure 5 is a flowchart showing the ignition timing calculation processing procedure, Figure 6 is a flowchart showing the torque reading procedure, and Figure 7 is a schematic diagram showing how to determine the base advance angle. Figure 8 is a time chart showing the change pattern of ignition timing torque, Figure 9 is a table showing the positive direction of ignition timing, Figure 1O is a diagram showing the relationship between ignition timing and torque, and Figure 11 is a diagram showing the relationship between ignition timing and torque. 1 shows the torque fluctuation state, FIG. 12 is a flowchart showing the torque reading procedure in the second embodiment of the present invention, and FIG. 13 shows the procedure for stopping the MBT control in the second embodiment. This is a flowchart. DESCRIPTION OF SYMBOLS 1... Engine, 4... Ignition coil, 7... Rotation angle sensor, 8... gil@l upper angle sensor, 14... Pressure sensor, 16... Torque sensor, 20...・Phase difference counting circuit, 21...Ignition setting circuit. Agent B1 Riju Takashi Okabe Figure 6 Start 1u Jis9・t! -7' Kosi≦MNT 353 SCrSi13"MNT 1 trout N2=N2÷im fsiG=I N. Th4Tn + 1 Tnn Tn+2 Tn=SiG/N2 fSiG20N2:0 ヱ" T,, >AYES Yosako TI, < BYES 61 ES362 Satoyoshi fFB = 0 Fig. 7 Fig. 8 Fig. 9 fls LO diagram Gennin Ginto 0 Fig. 12 Fig. 13

Claims (4)

[Claims] (1) Periodically change the ignition timing of the internal combustion engine, and adjust this ignition timing to the maximum ljs 114 square 4 (
In a method for controlling the ignition timing of an internal combustion engine that controls the internal combustion engine, a torque change detection means detects the occurrence of a torque change with the drive power transmission system of the internal combustion engine as the source.
L, when the occurrence of a predetermined torque change is detected, the self 11B self-stings ζ At the time of JJj, the maximum torque is obtained.
P, engine ignition n,) period 1jηDI method・ (2) Torque change J &
The output means is a torque sensor that directly outputs the torque generated by the internal combustion engine, and the output of the torque sensor is m
AQ Th of the output change amount of the torque sensor when it is equal to or more than the second setting value A, when it is equal to or less than the second setting A. Ignition timing control for an internal combustion engine according to claim 1, characterized in that when one of the two conditions is satisfied, the feedback control to the minimum advance angle α for obtaining the maximum torque at the time of ignition p and n is stopped. Method. (3) The torque change detection means for detecting the occurrence of a torque change is at least one of a clutch switch for detecting engagement and disengagement of a clutch of an internal combustion engine, and a shift sensor for detecting a shift of a transmission. An ignition timing control method for an internal engine as set forth in claim 1. (4) After the signals from the clutch switch and the speed change sensor are detected, the feedback control to the minimum advance angle α for obtaining the maximum amount and torque of the ignition timing described in iii is stopped for a certain set period. The ignition timing control method for an internal combustion engine according to scope 3.