JP2682649B2 - Engine ignition timing control device and ignition timing control method - Google Patents

Description

The present invention relates to an ignition timing control device for an engine, which sets an optimum ignition timing based on an engine speed and load data set based on the engine speed. The present invention relates to an ignition timing control method.

[Problems to be Solved by Conventional Techniques and Inventions] Conventionally, since high accuracy is required for measuring the intake air amount, in the L-Jetronic automobile engine, responsiveness is provided upstream of the throttle valve in the intake pipe of the automobile engine. An intake air amount sensor such as a hot film type air flow meter or a hot wire type air flow meter is provided. Since the intake air amount sensor of this type has a good responsiveness, its output pulsates even in the steady operation region due to the influence of the intake pulsation of the engine, as shown by the alternate long and short dash line in FIG. Therefore, conventionally, the output of the intake air amount sensor is uniquely averaged to obtain the intake air amount Qs'.

In the fuel injection control, the intake air amount Qs'
The basic fuel injection amount Tp is determined from the following equation based on the engine speed N and the engine speed N.

Tp = K · Qs ′ / N (K: constant) Then, the basic fuel injection amount Tp is corrected by various correction factors such as water temperature correction, acceleration correction, feedback correction, and the actual fuel injection amount Ti is calculated. The fuel injection control is carried out to suppress the enrichment or leaning of the air-fuel ratio.

On the other hand, in the ignition timing control, the basic fuel injection amount Tp obtained based on the intake air amount Qs ′ uniquely obtained by averaging is regarded as the engine load, and this basic fuel injection amount
It is known that an area of the ignition timing map is specified using Tp and the engine speed N as parameters, 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 in a transient state, the intake air amount Qs measured immediately after that by the intake air amount sensor is the intake air amount supplied to the cylinder, the air on the downstream side of the throttle valve. The flow rate that is the sum of the intake air amount required for pressure fluctuations in the chamber and intake manifold, 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 less than that. Have some delay.

For example, SPI (single point injection)
In the case of, the fuel is injected on the upstream side of the throttle valve, so it is only necessary to set the fuel injection amount that corresponds to the amount of air passing through the throttle.However, the ignition timing is actually drawn by the engine even if the fuel injection is the SPI method. It is necessary to set the amount of air (actual intake air amount).

As a result, the ignition timing during transition is calculated by averaging the output of the intake air amount sensor uniquely and calculating the intake air amount Q.
If the basic fuel injection amount Tp calculated based on s ′ is set as a control parameter, the ignition timing is temporarily retarded and it becomes impossible to control properly, resulting in a decrease in engine output, driving feeling, and exhaust gas. Emissions will deteriorate.

For example, in JP-A-61-229954 and JP-A-62-265449, the intake system of the engine is replaced with an electrical equivalent circuit to estimate the intake air amount actually taken into the engine even during a transient state. However, a technique has been disclosed in which this estimated value is used for ignition timing control. However, the intake air of the engine is actually drawn into the engine by replacing the intake system of the engine with an electrical equivalent circuit. Since the amount is indirectly estimated and this estimated value is used for ignition timing control, there is a limit to optimally controlling the ignition timing during transition using this estimated value.

Further, for example, in Japanese Patent Laid-Open No. 62-261645, the pressure downstream of the throttle valve is calculated from the function of the throttle valve opening and the air flow rate under atmospheric pressure measured by an air flow meter. Determine the amount of air charged to the chamber downstream of the throttle valve and the intake pipe during transition from the differential and the volume of the chamber downstream of the throttle valve and the intake pipe, and subtract the amount of air filled from the air flow rate measured by the air flow meter. Although a technique for estimating the actual intake air amount of the engine is disclosed, this prior art merely 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 the optimal control of the ignition timing during transition.

[Object of the Invention] The present invention has been made in view of the above circumstances, and it is possible to accurately calculate load data corresponding to a true intake air amount due to a change in throttle opening and a change in engine speed. An ignition timing control device and an ignition timing control method for an engine capable of setting an optimum ignition timing at a transition time using data as a parameter to improve an operation feeling, engine output performance, and exhaust emission. Is intended to provide.

[Means and Actions for Solving the Problems] (1) The engine ignition timing control device according to the present invention includes an engine speed calculating means for calculating an engine speed from an output signal of a crank angle sensor, and an intake air amount sensor. Throttle passing air amount calculating means for calculating the throttle passing air amount from the output signal, weighting coefficient calculating means for calculating a weighting coefficient from the engine speed calculated by the engine speed calculating means and a coefficient determined by the engine, and this time calculation The load data of this time is obtained by adding the ratio of the difference between the throttle passing air amount per engine revolution and the previously calculated load data and the weighting coefficient calculated by the weighting coefficient calculation means to the previously calculated load data. Load data calculation means, the current load data calculated by the load data calculation means, and the engine speed Ignition timing search means is provided for searching the ignition timing map from the ignition timing map using the engine speed of this time calculated by the rotation speed calculation means as a parameter.

(2) In the engine ignition timing control method according to the present invention, the engine speed is calculated from the output signal of the crank angle sensor, the throttle passing air amount is calculated from the output signal of the intake air amount sensor, and then the engine speed is set. Then, the weighting coefficient is calculated from the coefficient determined by the engine, and then the ratio between the difference between the throttle passing air amount per engine revolution calculated this time and the load data calculated last time and the weighting coefficient calculated this time is calculated last time. The present load data is calculated by adding it to the above load data, and the present ignition timing is searched from the ignition timing map using the present load data and the present engine speed as parameters. The load data is calculated by the formula.

First, when the engine speed is N and the coefficient determined by the engine is Kv, the weighting coefficient α is calculated by α = Kv / N, the previous time is (tn−1), and the current time is (t
n), and letting the amount of air passing through the throttle be Qs, this load data TQa (tn) Ask for.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

The drawings show an embodiment of the present invention, FIG. 1 is a schematic diagram of an engine control system, FIG. 2 is a functional block diagram of a control device, FIG. 3 is a flowchart showing a procedure for calculating ignition time, and FIG.
FIG. 6 is a front view of the crank rotor, FIG. 5 is a conceptual diagram showing an intake state, and FIG. 6 is a characteristic diagram showing an intake air amount.

(Structure) Reference numeral 1 in the drawing is an engine body, and in the drawing, a horizontally opposed four-cylinder engine is shown. Also, this engine body 1
An intake manifold 3 and an exhaust manifold 4 are respectively connected to an intake port 2a and an exhaust port 2b formed in the cylinder head 2, and the ignition portion of the cylinder head 2 is exposed to the combustion chamber 1a. A spark plug 5 is mounted.

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

A chamber A is constituted by the throttle chamber 7, the air chamber 6, the intake manifold 3 and the intake port 2a between the downstream side of the throttle valve 7a and the intake valve.

Further, an intake air amount sensor (a hot wire type air flow meter in the figure) 10 is interposed immediately downstream of the air cleaner 9 of the intake pipe 8, and a throttle valve 7a provided in the throttle chamber 7 has a throttle valve 7a. The position sensor 11 is provided continuously. Further, an injector 12 is arranged immediately upstream of the throttle valve 7a. A cooling water temperature sensor 13 is exposed to a cooling water passage (not shown) formed in the intake manifold 3.

On the other hand, a crank rotor 14 is fixedly mounted on the crank shaft 1b of the engine body 1.
A crank angle sensor 15 composed of an electromagnetic pickup or the like is provided on the outer periphery of 14 so as to face it.

As shown in FIG. 4, a projection 14a indicating the reference crank angle of each cylinder (# 1, # 2 and # 3, # 4) is provided on the outer periphery of the crank rotor 14, and a reference point for calculating the angular velocity. Become protrusion 1
4b are disposed at symmetrical positions.

For example, in the figure, the set angle θ1 of the protrusion 14b is shown.
Is BTDC 10 °, the opening angle θ2 of the protrusion 14a indicating the reference crank angle is 110 ° from the protrusion 14b, and the opening angle θ3 between this protrusion 14a and another protrusion 14b is set to 70 °. ing.

In the crank angle sensor 15, the crank rotor 14
A reference crank angle (G) signal for detecting the reference crank angle for each cylinder by taking out an AC voltage generated by a change in magnetic flux when each protrusion 14a, 14b of the cylinder 14 passes through the head of the crank angle sensor 15, and It outputs a rotation angle (Ne) signal to detect engine speed and angular velocity.

Further, an O2 sensor 17 faces an exhaust pipe 16 communicating with the exhaust manifold 4. Reference numeral 18 is a catalytic converter.

(Circuit Configuration of Control Means) On the other hand, reference numeral 19 is a control means, which is a CPU of the control means 19.
(Central processing unit) 20, ROM21, RAM22, and I / O interface 23 are connected to each other via a bus line 24, and each of the sensors 10, 11, 13 is connected to an input port of this I / O interface 2. The operating state parameter detecting means 25 composed of 15 and 17 is connected to the output port of the I / O interface 23, and the injector 12 is connected to the output port of the I / O interface 23 via a drive circuit 26. 5 is connected via a distributor 27 and an ignition coil 28.

Control program, ignition timing map MP IG
Fixed data such as is stored in the RAM22.
The output signals of the respective sensors of the operating state parameter detecting means 25 after data processing are stored in. Further, the CPU 20 calculates the fuel injection amount and the ignition timing based on the various data stored in the RAM 22 according to the control program stored in the ROM 21.

(Functional Configuration of Control Means) As shown in FIG. 2, the ignition timing control in the control means 19 is performed by the crank pulse discrimination means 29 and the angular velocity calculation means 3
0, engine speed calculation means 31, weighting coefficient calculation means 32,
Throttle passing air amount calculation means 33, load data calculation means
36, ignition timing search means 40, ignition timing map MP IG stored in ROM 21, ignition timing calculation means 41, timer means 4
2. The ignition drive means 43.

In the crank pulse determination means 29, the crank angle sensor 15
Of the crank rotor 14 is the Ne signal that detects the protrusion 14b.

That is, first, the time (T1) until the next input signal is measured with reference to the signal first input from the crank angle sensor 15, and then the time until the next signal is input with this signal as the reference. Time (T2) is measured.

If the two times are compared and T2 <T1, it can be predicted that the next input signal is a G signal (a signal for detecting a reference crank angle) for detecting the protrusion 14a of the crank rotor 14.

On the other hand, when T2> T1, it can be predicted that the next input signal is the Ne signal (reference signal for measuring the rotation angle) for detecting the protrusion 14b of the crank rotor 14. When the G signal is detected, a trigger signal is output to the timer means 42.

In the angular velocity calculating means 30, the crank pulse determining means
The time Tθ from the time when the Ne signal detected in 29 is detected until the time when the next G signal is detected is calculated, and the angle θ between the protrusions 14b and 14a of the crank rotor 14 stored in the ROM 21 in advance.
The angular velocity ω of the crankshaft 1b is obtained from the data of 2.

In the engine speed calculating means 31, the angular velocity calculating means
The engine speed N is calculated from the angular velocity ω calculated in 30.

The throttle passing air amount calculating means 33 calculates a throttle valve 7a and an ISCV (idle speed control valve, not shown) from the output waveform of the intake air amount sensor 10.
The amount of intake air Qs passing through the bypass passage is calculated.

The weighting coefficient calculating means 32 calculates the first-order lag time constant τ of the intake air amount sensor 10 from the engine speed N calculated by the engine speed calculating means 31, and the weighting coefficient (weighted average ratio) α = Calculate τ / Δt.

That is, the time constant τ is N: engine speed (rps) VC: chamber A internal volume (m ³ ) from downstream of throttle valve to immediately before intake valve ηV: inlet downstream condition, that is, chamber A internal pressure (Kg / m ² ), Volumetric efficiency with respect to chamber A temperature (° K) VH: Total exhaust volume (m ³ ) Of these, VC and VH are constant values for each engine, and ηV is considered to be minimally affected by the load, and can be usually treated as ηV≈1 or ηV = const.

Therefore, the time constant τ is Then, τ = Kv ′ / N (2) as a function of the engine speed N, and this time constant τ is a value inversely proportional to the engine speed N. Further, Δt is a time-dependent calculation cycle, which is determined by the control program and the calculation ability of the CPU 20 and is always constant without being influenced by the engine speed. Therefore, if Δt is included in the coefficient Kv ′ (Kv ′ / Δ
t = Kv), and the weighting coefficient α also becomes a value inversely proportional to the engine speed N.

α = τ / Δt = Kv ′ / (Δt × N) = Kv / N (2a) Therefore, the coefficient (coefficient determined by the engine) Kv is a constant value, and this coefficient Kv is obtained in advance and stored in the ROM 21. It may be stored as fixed data at a predetermined address and read out when the weighting coefficient α (tn) is calculated.

Further, in the load data calculating means 36, from the weighting coefficient α calculated by the weighting coefficient calculating means 32 and the throttle passing air amount Qs calculated by the throttle passing air amount calculating means 33,
The actual load data TQa (tn) at the current time is calculated.

That is, as shown in FIG. 5, the throttle valve 7
a, and the intake air amount Qs (Kg / sec) that passes through the air bypass passage of the ISCV (idle speed control valve) (not shown) is measured by the intake air amount sensor 10. Assuming that the measurement time and the time of the intake air passing through the throttle valve 7a and the like coincide, the intake air weight Wat (Kg) flowing into the chamber A per calculation cycle Δt is Wat = Qs × Δt ( 3) On the other hand, the actual intake air weight Wae in which the intake air flowing into the chamber A constituted by the air chamber 6, the intake manifold 3 and the intake port 2a is sucked into the combustion chamber 1a of each cylinder per time cycle. (Kg) is Wae = Q × Δt (4).

On the other hand, the actual intake air amount Q can be obtained from the volume flow rate Vae (m ³ / sec) per unit time in the chamber A and the air specific gravity ε in the chamber A.

Q = Vae × ε (5) Further, this volume flow rate Vae is N / Z; It can be calculated by the number of intake strokes per second of a 4-cycle engine.

The specific gravity of air ε is given by RC: Gas constant of air (kgm / kg ° K) TC: Air temperature in chamber A (° K) PC: Pressure in chamber A (Kg / m ² )

Therefore, the above equation (5) is Becomes

The specific gravity ε of the air in the chamber A is determined by the weight WC (Kg) of the air in the chamber A and the volume VC in the chamber A.
Since it is expressed as a ratio with (m ³ ), the above equation (8) is Can be transformed into

By the way, when the throttle passing air amount Qs and the actual intake air amount Q are grasped by the input / output relation in the chamber A, the air weight WC (tn) in the chamber A at a certain time (tn) is Chamber A at (tn-1)
The throttle intake air weight Wat (tn) newly introduced this time is added to the internal air amount WC (tn-1), and the actual intake air weight Wae sucked into the combustion chamber 1a is subtracted therefrom. It can be obtained by

Actual intake air weight Wae sucked into the combustion chamber 1a
The time of may be the time of the previous time (tn-1) and this time (tn), but if the actual intake air weight Wae (tn-1) of the previous time is assumed and the input / output relationship in the chamber A is expressed by a difference equation, , WC (tn) = WC (tn−1) + Wat (tn) −Wae (tn−1) = WC (tn−1) + Qs (tn) × Δt−Q (tn−1) × Δt (10) Become.

Further, assuming the actual intake air weight Wae (tn) this time, if the input-output relationship in the chamber A is expressed by a difference equation, WC (tn) = WC (tn-1) + Wat (tn) -Wae (tn) = WC (tn-1) + Qs (tn) * [Delta] t-Q (tn) * [Delta] t (10 ').

By the way, the time constant τ is as shown in the equation (1), and the equation (1) is substituted into the equation (8) to obtain the actual intake air amount Q.
WC = Q × τ, and the chamber air weight WC (t
n) is WC (tn) = Q (tn) × τ (tn) (11), and the chamber internal air weight WC (tn-
1) is WC (tn-1) = Q (tn-1) * [tau] (tn-1) (12).

By substituting the equations (11) and (12) into the equation (10) and solving for the actual intake air amount Q (tn) at this time, Therefore, since α = τ / Δt, Becomes

Further, by substituting the above equations (11) and (12) into the above equation (10 ') and solving for the actual intake air amount Q (tn) at this time, Becomes

[Alpha] (tn-1) and [alpha] (tn) in the equations (13a) and (13a ') are the previous and present weighting factors calculated by the weighting factor calculation means 32, and the actual intake air amount Q (T
n) is calculated by the weighted average by the weighting coefficient of this time and this time.

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

By the way, the coefficient of the above equation (13a) And the sum is α (tn-1) / α (tn). On the other hand, as shown in the equation (2a), the weighting factor α and the engine speed N are inversely proportional when the volumetric efficiency is constant. Therefore, the sum of the above coefficients during acceleration is And the sum of the coefficients at the time of deceleration is Since the weighting coefficient ratio (correction value) fluctuates according to the fluctuation of the engine speed, the followability of the actual intake air amount Q (tn) by the fluctuation of the engine speed is improved, and the actual intake air amount Q ( tn) can be calculated accurately.

The sum of the coefficients in the above equation (13a ') is And excluding Δt, As described above, the weighting coefficient ratio fluctuates following the fluctuation of the engine speed.

According to the experiment, as shown in FIG. 6, the actual intake air amount Q according to the above theoretical formula shows a value substantially equal to the true intake air amount sucked into the combustion chamber 1a obtained by the model in the entire operating region. It was

In the engine with a small volume VC in the chamber A, if the weighting coefficient α becomes too small in the high engine speed region, a lower limiter may be set for the weighting coefficient α.

By the way, the actual intake air amount Q (tn) does not correspond to the load, and in order to calculate the load data proportional to the engine torque from this actual intake air amount Q (tn), the actual intake air amount per time is calculated. Needs to be corrected to the actual intake air amount per engine revolution (= load data).

That is, if the load data (actual intake air amount per engine revolution) is TQa (tn), then TQa (tn) = Q (tn) / N (tn) (13b).

Therefore, if the above equation (13a) is converted into load data, Then, if this equation (13c) is transformed, Then, in the previous load data TQa (tn-1), the throttle passing air amount Qs per engine revolution calculated this time is calculated.
Add the value obtained by dividing the difference between (tn) / N (tn) and the previous load data (actual intake air amount per engine revolution) TQa (tn-1) by the weighting coefficient α (tn) this time. Thus, the load data TQa (tn) of this time is calculated.

Load data TQa calculated by the load data calculating means 36
(Tn) and the weighting coefficient α (tn) calculated by the weighting coefficient calculating means 32 are sequentially stored in a predetermined address of the storage means (RAM) 22.

In the ignition timing search means 40, the load data calculation means 36
The load data TQa (tn) calculated in step S1 and the engine speed N at that time calculated by the engine speed calculation means 31
The address of the ignition timing map MP IG is searched using (tn) as a parameter, and the ignition timing (ignition angle) θspk stored at the searched address is read.

The ignition time calculation means 41 calculates an ignition time Tspk based on the angular velocity ω calculated by the angular velocity calculation means 30 and the ignition timing θspk searched by the ignition timing search means 40 as Tspk = θspk / ω.

The ignition time Tspk is determined by the crank pulse determining means 29.
G signal output from the crankshaft (reference crank angle of the crank rotor 14, for example, a signal that detects the protrusion 14a indicating BTDC80 °)
Is set based on

The timer means 42 starts timing of the ignition time Tspk calculated by the ignition time calculation means 41 by using the G signal output from the crank pulse determination means 29 as a trigger signal, and when the ignition time Tspk is reached, the ignition drive means An ignition signal spk is output to the ignition coil 28 via 43.

The ignition time Tspk is the load data TQa calculated by the load data calculating means 36 based on the actual intake air amount Q (tn).
Since this is adopted as a load parameter, it has good followability during transients, and the optimum ignition timing can be set during transients as well as during steady operation.

(Operation) Next, the ignition timing control operation according to the above configuration will be described with reference to the flowchart of FIG.

First, in step S101, the crank pulse output from the crank angle sensor 15 is the G signal indicating the reference crank angle,
It is determined whether or not it is a Ne signal that indicates the reference when calculating the angular velocity.

Then, in steps S102 and S103, the angular velocity ω at the current time from the crank pulse input interval determined in step S101, and the engine speed N based on the angular velocity ω.
Calculate (tn).

Then, in step S104, the throttle passing air amount Qs (tn) is calculated from the output signal of the intake air amount sensor 10.

Then, in step S105, the weighting coefficient α (tn) is calculated by the equation (2a) based on the engine speed N calculated in step S103 and the time-dependent calculation cycle Δt (α (tn) = τ (tn ) / Δt = Kv / N (tn)). Note that τ
(Tn) is a time constant at the current time and is calculated by the above equation (1).

Then, in step S106, load data (actual intake air amount per engine revolution) TQa (tn) is calculated.

This load data TQa (tn) is calculated as the throttle passing air amount Qs (tn) / N (tn) per engine revolution.
And load data TQa (tn-1) calculated in the previous routine
Ratio (Qs (tn) / N (tn) -TQa (tn-1)) to the weighting coefficient α (tn) calculated in step S105. Is calculated by adding the previously calculated load data TQa (tn-1) (see equations (13) and (13d)).

When the program is the first time, since there is no previous load data TQa (tn-1), the process jumps from step S104 to step S107, and the engine speed N (tn) calculated in step S103 and the step S104 described above. Ratio (Qs (tn) / N) with the throttle passing air amount Qs (tn) calculated in
(Tn)) is stored in the storage means (RAM) 22 as the previous load data TQa (tn-1) and the routine is deviated.

On the other hand, if the program is the second or later,
The process proceeds from S106 to step S107, and the load data TQa of this time
(Tn) is the previous load data (TQa (tn) → TQa (tn-
1)) is stored in the storage means (RAM) 22.

Next, in step S108, the engine speed N (tn) calculated in steps S103 and S106 and the load data TQa (t
Using n) as a parameter, the ignition timing (ignition angle) θspk stored in a specific area (corresponding address) of the ignition timing map MP IG is searched.

Then, in step S109, the angular velocity ω calculated in step S102 and the ignition timing θ retrieved in step S108
Based on spk, an ignition time Tspk is calculated based on when a G signal for detecting the reference crank angle of the crank angle sensor 15 is output (Tspk = θspk / ω).

Then, in step S110, the ignition timing Tspk is set in the timer means 42, time measurement is started by using the G signal as a trigger signal, and when the set ignition time Tspk is reached, the ignition coil means 28 is sent to the ignition coil 28. The ignition signal spk is output, the primary winding of the ignition coil 28 is cut off, and the distributor 27 ignites the ignition plug 5 of a predetermined cylinder.

Thus, since the ignition timing θspk is obtained by taking in the load data TQa (tn) obtained from the actual intake air amount Q (tn) as a parameter, the optimum ignition is performed not only during the transition but also in the entire operating range. You can set the time.

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

[Effects of the Invention] As described above, according to the present invention, the weighting coefficient is calculated from the engine speed and the calculation cycle that depends on time, and the throttle passing air amount per one engine rotation calculated this time and the previous time are calculated. The load data calculated this time is calculated by adding the ratio of the difference between the calculated load data and the weighting coefficient to the load data calculated the last time. It is possible to accurately calculate the load data corresponding to the true intake air amount.

Further, since the present ignition timing is searched from the ignition timing map using the load data of this time and the engine speed of the present time as parameters, the optimum ignition timing at the time of transition is set using the load data as parameters. As a result, excellent effects such as driving feeling, improvement of engine output performance, and improvement of exhaust emission can be achieved.

[Brief description of the drawings]

1 is a schematic view of an engine control system, FIG. 2 is a functional block diagram of a control device, FIG.
4 is a front view of the crank rotor, FIG. 5 is a conceptual diagram showing an intake state, and FIG. 6 is a characteristic diagram showing an intake air amount. 10 ... intake air amount sensor, 15 ... crank angle sensor, 31
...... Engine speed calculation means, 32 …… Weighting coefficient calculation means, 36 …… Load data calculation means, 40 …… Ignition timing search means, Kv …… Engine determined coefficient, MP IG …… Ignition timing map, N ... … Engine speed, Qs …… Throttle passing air volume, TQa …… Load data, (tn) …… Current time, (tn−1) …… Previous time, Δt …… Computational cycle,
α: Weighting coefficient, θspk: Ignition timing.

Claims (3)

(57) [Claims] 1. An engine speed calculating means for calculating an engine speed from an output signal of a crank angle sensor; a throttle passing air amount calculating means for calculating a throttle passing air amount from an output signal of an intake air amount sensor; A weighting coefficient calculation means for calculating a weighting coefficient from the engine rotation speed calculated by the rotation speed calculation means and a coefficient determined by the engine, and a difference between the throttle passing air amount per engine rotation calculated this time and the load data calculated last time. , A load data calculation means for adding the ratio of the weighting coefficient calculated by the weighting coefficient calculation means to the previously calculated load data to calculate the current load data, and a current load calculated by the load data calculation means. Using the data and the current engine speed calculated by the engine speed calculation means as parameters, the ignition timing An ignition timing control device for an engine, comprising: an ignition timing search means for searching the ignition timing of this time. 2. An engine speed is calculated from an output signal of a crank angle sensor, a throttle passing air amount is calculated from an output signal of an intake air amount sensor, and a weighting coefficient is calculated from the engine speed and a coefficient determined by the engine. Then, the ratio of the difference between the throttle passing air amount per engine revolution calculated this time and the load data calculated last time and the ratio of the weighting coefficient calculated this time is added to the load data calculated last time to obtain the load data this time. An ignition timing control method for an engine, comprising calculating and searching the ignition timing of this time from an ignition timing map using the load data of this time and the engine speed of this time as parameters. 3. When the engine speed is N and the coefficient determined by the engine is Kv, the weighting coefficient α is obtained by α = Kv / N, and the previous time is (tn-1) and the current time is (tn).
n), and letting the amount of air passing through the throttle be Qs, this load data TQa (tn) 3. The engine ignition timing calculation method according to claim 2, wherein