JPH0227162A - Engine ignition timing control device and ignition timing adjustment method - Google Patents

Abstract

PURPOSE:To improve the feel of driving by retrieving present ignition timing from an ignition timing map, using as parameters present load data calculated by a load data calculating means and present engine revolution calculated by an engine revolution calculating means. CONSTITUTION:An engine revolution is calculated from an output signal from a crank angle sensor 15, and a throttle passing air volume is calculated from an output signal from an intake air flow sensor 10. A weighting coefficient alphamemorized in a weighting coefficient map MPa is retrieved, using as parameters the engine revolution and the throttle opening as detected by a throttle position sensor 11. Later, present load data is calculated by adding to the previously calculated load data a ratio of the difference between the throttle passing air volume per a revolution of engine as calculated this time and the previously calculated load data to the weighting coefficient as calculated this time. With present load data and present engine revolution as parameters, present ignition timing is retrieved from the ignition timing map MPIG.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention is directed to an engine ignition timing control device that sets the optimum ignition timing from engine rotational speed and load data set based on this engine rotational speed. J; and ignition timing control method.

``Problems to be solved by conventional technology and inventions'' Conventionally, since high accuracy was required for intake air amount measurement, L-ji J1~
In Ronik's automobile engines, an intake air amount sensor such as a highly responsive hot film air flow meter or hot wire airflow meter is installed upstream of the throttle valve in the intake pipe of the automobile engine. Since this type of intake air amount sensor has good responsiveness, its output pulsates as shown by the dashed line in FIG. 6 even in a steady operating range due to the influence of the intake pulsation of the engine. For this reason, conventionally, the intake air IQs is determined by uniquely averaging the output of one meter of airflow.

In addition, in fuel injection control, the intake air itQs
The basic fuel injection amount Tp is determined from ' and the engine speed N using the formula below.

Tp=-Qs'/N (K: constant) Then, this basic fuel injection DI m Tp is corrected by various correction coefficients such as water temperature correction, acceleration correction, feedback correction, etc.
Determine the actual fuel injection amount 7i, perform fuel injection control based on this, and suppress the enrichment or leanness of the air-fuel ratio.
I try to do that.

On the other hand, when controlling the ignition timing, the basic fuel injection amount Tρ obtained based on the intake air amount Q s ' obtained through averaging processing is taken as the engine load, and this basic fuel injection i T D and the engine speed are It is known that an area of the ignition timing map is specified using the number N as a parameter, and the ignition timing stored in this area is used as the actual ignition timing.

By the way, when the throttle valve is suddenly opened during a transient situation, the intake air fflQs detected by the intake air amount sensor immediately after is equal to the intake air amount supplied to the cylinder and the downstream side of the throttle valve. The amount of intake air required for pressure fluctuations in the air chamber and intake manifold is added to the flow rate, that is, the air flow rate that has passed through the throttle valve is measured, so the actual amount of air taken into the cylinder is It has a certain delay.

For example, in the case of SPT (Single Point Injection), fuel is injected upstream of the throttle valve, so it is only necessary to set the fuel injection amount corresponding to the amount of air passing through the throttle. Even with this method, it is necessary to set the amount of air actually taken in by the engine (actual intake air amount).

As a result, the ignition timing during the transient period is calculated by uniquely averaging the output of the intake air amount sensor.
If the basic fuel quantity Tp determined based on This will lead to deterioration of emissions.

For example, JP-A-61-229954, JP-A-62-
2 6 5 4. 4 Publication No. 9 states that the intake system of the engine is replaced with an electrical equivalent circuit, the amount of intake air actually taken into the engine is estimated even during transient periods, and this estimated value is used for ignition timing control. However, this technique involves simply replacing the engine intake system with an electrical equivalent circuit, indirectly estimating the intake air h± per cycle that is actually drawn into the engine, and calculating this estimated value. Since it is used for ignition timing control, there is a limit to how well this estimated value can be used to appropriately control the ignition timing during transient times.

Also, for example, in Japanese Patent Application Laid-Open No. 62-261645,
Calculate the pressure downstream of the throttle valve from a function based on the distance between the valves and the air under atmospheric pressure measured by an air flow meter > Mfi, and calculate the time derivative of this pressure and the pressure downstream of the throttle valve. From the volumes of the chamber and intake pipe, find the amount of air filling in the chamber downstream of the throttle valve and the intake pipe during a transient period, and subtract the amount of filling air from the air flow rate measured with the air flow meter. A technique for estimating the actual intake air amount of an engine has been disclosed, but this prior art only estimates the actual intake air amount of the engine based on the throttle valve opening. When used for ignition timing control, there is a limit to optimally controlling ignition timing during transient times.

[Object of the Invention] The present invention has been made in view of the above circumstances, and is capable of generating load data that corresponds to the true intake air amount due to changes in throttle opening and changes in engine speed, without using a large-capacity microcomputer or the like. can be calculated accurately in a short time, and this load data can be used as a parameter to set the optimal ignition timing during transient conditions, improving driving feeling, engine output performance, and exhaust emissions. It is an object of the present invention to provide an ignition timing control device and an ignition timing control method for an engine that can improve the engine ignition timing control method.

[Means and effects for solving the problems] (1) The engine ignition timing control device according to the present invention includes an engine rotation speed calculation means for calculating the engine rotation speed from the output signal of the crank angle sensor, and an intake air amount sensor. Throttle passing air amount calculation means calculates the amount of air passing through the throttle from the output signal, and the engine speed calculated by the engine speed dedicated means and the throttle opening detected by the throttle position sensor are stored in a weighting coefficient map as parameters. A weighting coefficient search means searches for a weighting coefficient that is searched by the weighting coefficient search means, and calculates the ratio between the difference between the currently calculated amount of air passing through the throttle per engine revolution and the load data calculated last time, and the weighting coefficient searched by the weighting coefficient search means. , Calculate the current load data by adding it to the load data calculated last time. An ignition timing search means for searching the current ignition timing from the ignition timing map using the current engine speed as a parameter is provided.

(2) The engine ignition timing control method according to the present invention calculates the engine speed from the output J signal of the crank angle sensor, calculates the amount of air passing through the throttle from the output signal of the intake air amount sensor, and further calculates the amount of air passing through the throttle from the output signal of the intake air amount sensor. The weighting coefficient stored in the weighting coefficient map is searched using the rotation speed and the throttle opening detected by the throttle position sensor as parameters, and then the currently calculated amount of air passing through the throttle per engine revolution and the previously calculated load data are calculated. The current load data is calculated by adding the ratio of the difference between The current ignition timing is searched from the ignition timing map, and load data is preferably calculated using the following formula.

That is, when the previous time is (t n -1), the current time is (tn), the amount of air passing through the throttle is Qs, and the weighting coefficient is α, the current load data T Qa (In) is obtained.

[Embodiments of the invention] Hereinafter, the present invention will be described in detail with reference to the drawings.

The drawings show one embodiment of the present invention, in which Fig. 1 is a schematic diagram of an engine control system, Fig. 2 is a functional block diagram of a control device, and Fig. 3 is a schematic diagram of an engine control system.
4 is a front view of the crank rotor, FIG. 5 is a conceptual diagram showing the intake state, and FIG. 6 is a characteristic diagram showing the amount of intake air.

(Configuration) Reference numeral 1 in the figure is the engine body, and the figure shows a horizontally opposed four-cylinder engine. In addition, an intake boat 2a, 1 no. 1 formed on the cylinder head 2 of this engine body 1
An intake manifold 3 and a exhaust manifold 4 are respectively connected to the air port 2b, and the cylinder head 2 is further equipped with a spark plug 5 whose ignition part is exposed to the combustion chamber 1a. ing.

Furthermore, the intake manifold 3 is connected to the intake manifold 3 on the upstream side via the air chamber 6 with the intake manifold 3 and the intake manifold 3.
The upstream side of the throttle chamber 7 is connected to an air cleaner 9 via a suction pipe 8.

Note that a chamber A is constituted by the throttle chamber 7, air chamber 6, intake manifold 3, and intake boat 2a from the downstream side of the throttle valve 7a to the intake valve.

Furthermore, an intake air amount sensor (in the figure, a Holato wire air flow meter) 10 is interposed immediately downstream of the air cleaner 9 in the intake pipe 8, and a throttle valve 7a provided in the throttle chamber 7 is connected to a throttle position sensor 10. Renly-11 is installed in series. Further, an injector 12 is disposed immediately upstream of the throttle valve 7a. Further, a cooling water temperature sensor 13 faces a cooling water passage (not shown) formed in the intake manifold 3.

On the other hand, 1b to the crankshaft t771 of the engine body 1
A crank rotor 14 is fixedly attached to the crank rotor 14, and a crank angle plate 15 consisting of an electromagnetic pickup or the like is disposed opposite to the outer periphery of the crank rotor 14.

As shown in FIG. 4, on the outer periphery of the crank rotor 14 there are protrusions 14a that indicate the reference crank angle of each cylinder (#1, #2 and #3, #4), and a reference point for calculating the angular velocity. Protrusion 14. b are arranged at symmetrical positions.

For example, in the figure, the set angle θ1 of the protrusion i 4 b is BTOCloo, and the opening angle θ2 of the protrusion 14 a indicating the reference crank angle is from the protrusion 14 b to 11
At 0°, this protrusion 14. a and other protrusions 14b
The opening angle O3 between the two is set to 70'.

In the crank angle sensor 15, the crank rotor 1
Each protrusion 1/l-a, 14b of 4 corresponds to the crank angle
A reference crank angle (G) signal for detecting the reference crank angle for each cylinder by extracting the alternating current voltage generated by changes in magnetic flux when passing through the head of No. 5, and rotation for detecting the engine speed and angular velocity. Outputs an angle (Ne) signal.

Furthermore, an 02 sensor 17 is placed facing an exhaust pipe 16 that communicates with the exhaust manifold 4. In addition, the code|symbol 18 is a catalytic converter.

(Circuit configuration of control means) On the other hand, reference numeral 19 is a control means, and the cp of this control means 19 is
u <central processing unit)20. ROM21, RAM2
2, and an I10 interface 23 are connected to each other via a pass line 24, and each of the above-mentioned sensors 10.11 is connected to the input port of this I10 interface 23.
, 13, 15, and 17 are connected, and this I10 interface]
, - the injector 12 is connected to the output port of the distributor 23 via a drive circuit 26, and the spark plug 5 is connected to the distributor 2 via an ignition coil 28.

The ROM 21 contains a control program and a weighting coefficient map M.
Fixed data such as Pα, ignition timing maps MPIG/, i, etc. are stored, and the RAM 22 stores output signals of each sensor of the operating state parameter detection means 25 after data processing. In addition, the above CPU20
Then, according to the control program stored in the ROM 21, the fuel injection amount and ignition timing are calculated based on various data stored in the RAM 22.

(Functional configuration of control means) As shown in FIG. 2, the ignition timing control in the control means 19 includes two crank pulse discrimination means, an angular velocity calculation means 30, an engine rotation speed calculation means 31, a weighting coefficient search means 32, a weight Coefficient map MPα, throttle passing air suspension calculation means 33, load piggy calculation means 36, ignition timing search means/10, ignition timing map MPIG stored in ROM 21, ignition time calculation means 41, timer means 42, ignition It is composed of a driving means 43.

In the crank pulse discrimination means 29, the crank angle sensor 1
It is determined whether the output signal No. 5 is a G signal that detects the protrusion 14a of the crank rotor 14 or a Ne signal that detects the protrusion 14b.

In other words, first, the time (T1) until the next input signal is measured from the first input signal Y from the crank angle sensor 1-15, and then this signal is used as the reference signal. The time (T2) until the next input signal is calculated if!l-S+-.

Then, by comparing the above-mentioned setting times, if T2<T1, it can be predicted that the next input signal is the G signal (signal for detecting the reference crank angle) for detecting the protrusion 14a of the crank rotor 14.

On the other hand, if T2>TI, it can be predicted that the next input signal is the Ne signal (reference signal when measuring the rotation angle) for detecting the protrusion 14b of the crank rotor 14. When the G signal is detected, the timer means 4
Outputs the 1~Riga signal to 2.

The angular velocity calculating means 30 calculates the time Tθ from when the Ne signal determined by the crank pulse determining means 29 is detected to when the next G signal is detected, and calculates the time Tθ from when the Ne signal determined by the crank pulse determining means 29 is detected to when the next G signal is detected, and calculates the time Tθ from the time when the Ne signal determined by the crank pulse determining means 29 is detected. 14b,
From the data of the angle θ2 between 14a and 14a, the crankshaft 1b
Find the angular velocity ω.

The engine speed calculation means 31 calculates the engine speed N from the angular speed ω calculated by the angular speed calculation means 30.

The throttle passing air amount calculating means 33 calculates the intake air amount Qs that passes through the throttle valve 7a and the bypass passage of an unillustrated 15CV (idle speed control valve) from the output waveform of the intake air amount sensor 10.

The weighting coefficient search means 32 uses the engine speed N calculated by the engine speed calculation means 31 and the throttle opening θT11 detected by the throttle position sensor 11 as parameters to retrieve the weighting coefficient map MPα stored in the ROM 21. Search for the weighting coefficient (weighted average ratio) α from . The engine speed N of this weighting coefficient map MPα
A weighting coefficient α determined in advance through experiments or the like is stored in the area specified by the throttle opening degree θ/month 1.

By the way, the above-mentioned weighting coefficient α can also be obtained by calculating 1:1, but by mapping it, the calculation time can be shortened. In addition, since the weighting coefficient α is searched using parameters such as engine speed N and throttle opening θTH, for example, it is possible to prevent blowback in the low engine speed range and fluctuations in volumetric efficiency due to changes in throttle valve opening. You can take it into consideration.

Note that the weighting coefficient α is calculated using the following formula.

The above weighting coefficient α is the first-order lag time constant τ differentiated by the time-dependent performance period Δt (α-τ/Δ1), and this -th-order lag time constant τ is calculated as follows: N: Engine rotation speed (rps) VC varnish [''Inner volume of chamber A from downstream of the throttle valve to just before the intake valve (TrL3) ηV: The condition that the input groove 9 is downstream of the throttle, that is,
The volumetric efficiency Vll for the pressure inside the chamber Δ (Kg/'rIL) and the degree of stagnation inside the chamber A (°K) is determined by: total displacement (m3). Of these, vc and VH are constant values for each engine, and ηV is considered to be slightly affected by load, so it is usually ηv #1 or ηV = const
(However, the above-mentioned volumetric efficiency ηV in a low engine speed range varies due to the influence of blowback, etc.).

Therefore, if the above time constant τ is ηVXVI+, then as a function of the engine speed N, τ−K v'
/ N ... expressed as (2),
This time constant τ becomes a value inversely proportional to the engine speed N. In addition, 4t is a calculation period that depends on time, is determined by the control program and the calculation power of the CPU 20, and is always constant without being affected by the engine speed, so if dt is included in the coefficient KV', then (Kv'/lU
t = Kv ), and the weighting coefficient α is also a value inversely proportional to the engine speed N.

rx −τ/at=Kv'/ (atXN)=Kv/
N...(2a) In addition, the load data calculation means 36'C calculates the weighting coefficient searched by the weighting coefficient searching means 32 and the throttle passing air kl calculated by the throttle passing air amount calculating means 33.
From Qs, the actual load data TQa(
Calculate tn).

Rinawara, J shown in Figure 5: Sea urchin, throttle valve 7
a, and the intake air passing through the air bypass passage of 15CV (idle speed control valve), not shown! tQs (Q/5eC) is measured by the intake air amount sensor 10, and if the time measured by the intake air amount sensor 10 and the time of the intake air passing through the throttle valve 78 etc. match, then Assuming that the intake air amount IW flowing into the chamber A per calculation period Δt is
aI(nig) is Wat=Qs x A t
・=(3), and on the other hand, the above construction) 7 chamber 6, data manifold 3, and suction port 2
The actual intake air weight Wae (K(1)), which is sucked into the combustion chamber 1a of each cylinder into the combustion chamber 1a of each cylinder per time period, is Wae-Q x l t-(4
).

On the other hand, the actual intake air amount Q is the volumetric flow rate V ae (rrt3/5ec
) and the specific gravity ε of the air in this chamber A.

Q = -V aexε
...(!i) Also, since this volumetric flow rate Vae is expressed as a ratio to the internal volume VC (m") of the chamber A, the above (!
8) The formula is ? N/2: It can be found by the number of intake strokes of 1 δec of a 4-cycle engine.

In addition, the air specific gravity ε is determined by the equation of state as CXTC [C: gas constant of air (kgm/ka'
-C nib j7 Air temperature in chamber A 1ff (°K) PC: Can be determined as pressure in chamber A (in 0/m').

Therefore, the formula (5) in -1- is, bawl.

Further, the specific gravity ε of the air in the chamber A can be transformed into the chamber with the air weight Wc (Kg) in the chamber.

By the way, when the above-mentioned throttle passing air filQs and the above-mentioned actual intake air ff1Q are considered in the input/output relationship in the above-mentioned chamber A, the air amount 1tWC (tn) in the chamber A at a certain time (tO) is equal to the previous time (tn). -1), the amount of air in chamber A WC (tn-1) is the weight of intake air passing through the throttle Wat (tn-1) newly introduced this time
n) and subtracting the actual intake air weight Wae drawn into the combustion chamber 1a from there.

Actual intake air weight Wa drawn into the combustion chamber 1a
The time e may be the previous time (tn-1) and the current time (tn), but the previous actual intake air weight W ac (tn-1
) and express the input/output relationship in chamber A using a differential equation, WC(tn) =WC(tn-1) +Wat(tn)
-Wae(tn-1)=WC(tn-1)+Q 5
(tn)x l tQ (jn-1)x Δ t
-(10)

Also, assuming the actual intake air weight W ae (tn), the input-output relationship in chamber A is expressed by a differential equation: WC (tn) = WC (tn-1) + Wat (tn)
-Wae(tn)=WC(tn-1)+Q5(
tn) x l tQ (tn) x a t −(
10°).

By the way, the time constant τ is as shown in equation (1) above,
Substituting equation (1) into equation (8) above and solving for the actual intake air amount Q, we get WC = QXτ, and the air weight inside the cabin at this time Wc (
tn) is WC(tn) = Q (tn)x r (In)
-(11), the air weight WC(t r+ -1) in the chamber at the previous time is WC(tn-1) = Q(tn-1)x r(t
n-1) ・(12).

Substituting these equations (11) and (12) into the above equation (10) and solving for the actual intake air fi Q (tn) at this time, we get: Since α-τ/Zt, α(tn ) α(tn)...(13
a) It becomes.

In addition, the above equations (11) and (12) can be converted into the above (10')
Substituting into the equation, the actual intake air fiQ(t
n), we get τ(tn-1)...(13°)...(13a').

The above equation (13a), (13a' α(tn-1) of equation 1)
, and α(tn)i are the previous and current weighting coefficients searched by the weighting coefficient search means 32, and the actual intake air amount Q (1n) is determined by the weighted average of the previous and current weighting coefficients. It will be done.

In this embodiment, the load data is calculated by employing equation (13a), which is close to the conventional equation for calculating the actual intake air amount Q (tn) from a weighted average.

By the way, the sum of the coefficient α(tn) αBn) in the above equation (13a) is α(tn-1)/αBn), and on the other hand, as shown in the above equation (2a), this weighting coefficient α and the engine rotation speed Since N is inversely proportional when the volumetric efficiency is constant, the sum of the above coefficients during acceleration is α(1n), and the sum of the coefficients during deceleration is α(tn), and the engine rotation Since the weighting coefficient ratio (correction value) changes according to the change in the number, the tracking ability of the actual intake air IQ (tn) due to engine speed fluctuations becomes better, and the actual intake air IQ (tn) can be accurately determined even during transient times. It can be calculated.

Note that the sum of the coefficients in equation (13a') above is α(tn-1
)+Δt α(tn)+J t , and if 7t is excluded, α(tn-1) α(tn) As described above, the weighting coefficient ratio changes following the fluctuation of the engine speed.

According to experiments, as shown in Fig. 6, the actual intake air amount Q based on the above theoretical formula is approximately equal to the true intake air amount taken into the combustion chamber 1a determined by the model over the entire operating range. Ta.

In addition, in an engine with a small volume VC within the above-mentioned balance △, if the weighting coefficient α becomes too small in the engine high speed range, a lower limiter should be set for the weighting coefficient α.
RuJ: You can do it.

By the way, the above actual intake air 11Q (tn) does not correspond to the load, but this actual intake air fi Q (tn)
In order to calculate load data proportional to engine torque, it is necessary to correct the actual intake air amount per hour to the actual intake air amount per engine revolution (-negative J data).

In other words, negative ten? I? If i data (actual intake air amount per engine revolution) is -Qa(tn), then T
Qa (tn) -〇 (Un)/N (tn)
・(13b) becomes.

Then, the IC converts the above equation (13a) into load data.
- then αBn) α(tn) and 4r. If we transform this equation (13c), we get The current load data TQa(tn) is calculated by weighting the difference from TQa(tn-1) (actual intake air amount per air) divided by the current weighting coefficient α(tn). Become.

Load data T calculated by the load data calculation means 36
Qa(tn) and the weighting coefficient α(Un) searched by the weighting coefficient search means J32 are stored in the storage means (RAMM) 2.
The data are sequentially stored at two predetermined addresses.

In the ignition timing search means 40, the load data calculation means 3
The address of the ignition timing map MPIG is searched using the load data T Qa (tn) calculated in step 6 and the engine speed N (tn) at that time calculated by the engine speed calculation means 31 as parameters, and this search is performed. The ignition timing (ignition angle) θs l)k stored in the address
Read.

In the ignition time calculation means 41, the angular velocity calculation means 30'
c. Ignition time based on the calculated angular velocity ω and the ignition timing θspk searched by the ignition timing search means 40 ]-sp+
is calculated as Tspk-θspk/ω.

This ignition time Tspk is determined by the G signal outputted from the two crank pulse discriminating means (a protrusion 1/l indicating a semi-crank angle of the crank rotor 14, for example, 80° BTDC).
The signal detected by a) is set as a reference.

In the timer means 42, the crank pulse discriminating means 29
The ignition time calculating means 41 starts counting the ignition time 7' spk calculated by the ignition time calculation means 41 using the G signal outputted from the 1-rega signal, and when the ignition time reaches the lower ignition time spk, the ignition coil is activated via the ignition driving means 43. The ignition signal spk is output to 28.

The ignition time Tspk is determined by the load data calculation means 36.
Since the load data TQa calculated based on the actual intake air IRQ (tn) is incorporated as a load parameter, it has good followability in transient situations, and it is possible to set b@appropriate ignition timing not only in steady-state operation but also in transient situations. can.

(Operation) Next, the third section regarding the ignition timing control operation with the above configuration.
The explanation will be given according to the flowchart shown in the figure.

First, in step 5101, it is determined whether the crank pulse output from the crank angle sensor 15 is a G signal indicating a reference crank angle or a J-Ne signal indicating a reference for calculating angular velocity.

Then, in steps 3102 and 5103, the current angular velocity ω and the engine rotation speed N (tn) based on this angular velocity ω are calculated from the crank pulse input interval determined in step 5101.

After that, in step 5104, the throttle passing air ff108 (tn) is determined from the output horn signal of the intake air amount sensor 10.
Calculate.

Then, in step 5105, the slot 1 health range θ■(t n
), and the suit knob 5106 calculates the engine rotation speed N (tn) calculated in step 5103 above and the speed 1 calculated in step 5103 above.
Weighting coefficient map MPα using publication 1 (tn) as a parameter
Find the weighting coefficient α (syn) from υ. .

Thereafter, in step 8107, load data (engine 1
Calculate TQa (tn) (Actual intake air amount per revolution) 1゜This load data 1Qa (tn) is calculated based on the air passing through the thrower 1 heel per rotation of the engine 1) Qs (t
What is the difference between n)/N(tn) and the load data T-Qa(tn-1) calculated in the previous routine (Q 5(tn)/
N (tn)-T Qa(tnl)) and the weighting coefficient α retrieved in step 8106 above is weighted with the load data 7 Qa(tn-1) previously calculated (((
13), see equation (13d)).

Note that when the program is started for the first time, there is no previous load data T Qa (tn-1), so step 510 is not performed.
4 to step 8108 and step S above.
The engine rotation speed N (tn) calculated in step 103 and the passing air M calculated in step 5104 above
The ratio to tQS(tn) (Q 5(tn) / N (t
n)) is stored in the storage means (RAM) 22 as the previous load 1-Qa (tn-1), and the routine exits.

On the other hand, if the program is being run for the second time or later, step 5 above
Proceeding from step 107 to step 8108, the current load data TQa (tn) is converted to the previous load data (T Qa (tn)
->T Qa(tn-1) ) as the storage means (R
AM) 22.

Next, in step 5109, the engine speed N (tn) and load data TQa (tn) calculated in steps 5103 and 3107 are stored in a specific area (corresponding address) of the ignition timing map M P IG as parameters. Search for ignition timing (ignition angle) θspk.

Thereafter, in step 5110, the G signal for detecting the reference crank angle of the crank angle sensor 15 is output based on the angular velocity ω calculated in step 8102 and the ignition timing Ospk retrieved in step 5109. Calculate the reference ignition time 1-spk (T
5pk-θspk/ω).

Then, in step 5111, the ignition time T spk
is sent to the cellar 1 by the timer means 42, and 4 o'clock is started using the G signal as a trigger signal, and the set ignition time Ts
When pk is reached, an ignition signal spk is output to the ignition coil 28 via the ignition driving means 43, the primary winding of the ignition coil 28 is cut off, and the distributor 27 outputs the ignition signal spk to the ignition coil 28, and the distributor 27 outputs the ignition signal spk to the ignition coil 28. ignite.

In this way, the load data TQa (tn) obtained from the above actual intake air m It is possible to set the optimum ignition timing in the region.

In addition, since the weighting coefficient α is mapped, the weighting coefficient value that takes into account the throttle opening angle θ in the low rotation range and the variation in volumetric efficiency due to the influence of blowback can be determined and set in advance through experiments. Not only is it possible to reduce calculation time, it is possible to reliably prevent temporary lag during transitions, and the feeling in the gold driving range is improved.

In this embodiment, time-controlled ignition IVY control has been described, but it goes without saying that the present invention can also be applied to angle-controlled ignition timing control.

[Effects of the Invention] As explained above, according to the present invention, the weighting coefficient stored in the weighting coefficient map is searched using the engine speed and throttle opening as parameters, and The current load data is calculated by adding the difference between the amount of air passing through the throttle and the previously calculated load data and the weighting coefficient above to the previously calculated load data. Change throttle opening without using a microcomputer, etc.
It is possible to accurately calculate load data corresponding to the true amount of intake air as the engine speed changes.

Furthermore, since the current ignition timing is searched from an ignition timing map that uses the current load data and the current engine speed as parameters, it is possible to maintain a steady state at low cost without using a large-capacity microcomputer. It is possible to quickly and accurately calculate load data that corresponds to the true intake air amount due to throttle opening changes and engine speed changes in all operating ranges, including not only the rotation range but also the low rotation range and high rotation range. Moreover, it is possible to set the optimum ignition timing during transient conditions, improving the driving feeling,
In addition, excellent effects such as improved engine output performance and improved exhaust emissions can be achieved.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, in which Fig. 1 is a schematic diagram of an engine control system, Fig. 2 is a functional block diagram of a control device, and Fig. 3 is a schematic diagram of an engine control system.
4 is a front view of the crank rotor, FIG. 5 is a conceptual diagram showing the intake state, and FIG. 6 is a characteristic diagram showing the amount of intake air. 10... Intake air amount sensor, 11... Throttle position sensor, 15... Crank angle sensor, 31
...Engine speed calculation means, 32... Weighting coefficient search means, 36... Load data calculation means, 40... Ignition timing search means, MPIG... Ignition timing map, MP
U... Weighting coefficient map, N... Engine speed, Q
s...Amount of air passing through the throat 1 heel, TQa...Load data, ([0)...Current time, (tn-1)...
Previous time, α... Weighting coefficient, θspk... Ignition timing.

Claims (3)

[Claims] (1) An engine rotation speed calculation means for calculating the engine rotation speed from the output signal of the crank angle sensor; and a throttle passage air amount calculation means for calculating the throttle passage air amount from the output signal of the intake air amount sensor; weighting coefficient search means for searching for a weighting coefficient stored in a weighting coefficient map using the engine rotation speed calculated by the calculation means and the throttle opening detected by the throttle position sensor as parameters; load data calculation means for calculating current load data by adding the ratio between the difference between the amount of passing air and the load data calculated last time and the weighting coefficient searched by the weighting coefficient search means to the load data calculated last time; An ignition timing search means is provided for searching the current ignition timing from the ignition timing map using the current load data calculated by the load data calculation means and the current engine speed calculated by the engine speed calculation means as parameters. An engine ignition timing control device characterized in that: (2) Calculate the engine speed from the output signal of the crank angle sensor, calculate the amount of air passing through the throttle from the output signal of the intake air amount sensor, and set the engine speed and the throttle opening detected by the throttle position sensor as parameters. The weighting coefficient stored in the weighting coefficient map is searched for, and the ratio of the difference between the amount of air passing through the throttle per engine rotation calculated this time and the load data calculated last time, and the weighting coefficient searched this time is calculated from the previous time. The current load data is calculated by adding it to the calculated load data, and the current ignition timing is searched from an ignition timing map using the current load data and the current engine speed as parameters. Ignition timing control method. (3) The previous time is (tn-1) and the current time is (tn
), the amount of air passing through the throttle is Qs, and the weighting coefficient is α, then the current load data TQa(tn) is TQa(tn) = TQa(tn-1) + [1/α(tn)] {[Qs( tn)/N(tn)]
3. The engine ignition timing calculation method according to claim 2, wherein the ignition timing is calculated as follows.