JPH0367065A - Ignition timing control device of internal combustion engine - Google Patents

Abstract

PURPOSE:To control the ignition timing properly by deciding the angle advance amount according to the acceleration level depending upon the degree of throttle valve opening, engine revolving speed, and car speed under acceleration, and subjecting the basic ignition timing to correction through addition of this angle advance amount. CONSTITUTION:As a crank angle position, the basic ignition timing corresponding to the steady operating condition is set by a basic ignition timing setting means on the basis of the engine operating condition sensed by an operating condition sensing means, and a measuring means determines the period of reference signal cycles from the reference signal for a specified crank angle position given by a reference signal generating means. Then a time calculating means determines the time from the reference signal to the basic ignition timing, and when this time is attained, an ignition signal is emitted. If an acceleration judging means judges that it is under acceleration, an at-acceleration basic ignition time correcting means makes correction of the basic ignition timing through adding of the angle advance amount corresponding to the acceleration level dependent upon the degree of throttle opening, engine revolving speed, and car speed. Thus a proper ignition timing control is achieved.

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to an ignition timing control device for an internal combustion engine. The present invention relates to an ignition timing control device that controls ignition based on the time from a reference signal generated at .

<Conventional technology> Conventionally, in electronically controlled ignition timing control devices for internal combustion engines,
The ignition timing (ignition advance) is set as the crank angle position based on the engine operating state, and ignition is performed by outputting the ignition signal at this timing. Generates a reference signal at a predetermined crank angle position, and also generates a reference signal at a crank angle of 1″ or 2°
Using a crank angle sensor that generates a unit signal for each cylinder, the system measures the number of unit signals generated after the reference signal for each cylinder is generated and determines the crank angle position to perform ignition at the set ignition timing. This is common.

However, a crank angle sensor having a unit signal generation function requires high accuracy and is expensive.

Therefore, by using a crank angle sensor that only has a reference signal generation function, the cycle of the reference signal (time from the previous reference signal) is known when the reference signal is generated, and based on this cycle, the time from the reference signal to the ignition timing is calculated. A time control method is being considered in which the ignition signal is calculated and the ignition signal is output when the time elapses to cause ignition. Furthermore, Japanese Patent Publication No. 61-286584
A time-controlled system is disclosed in the publication, although it is intended for fail-safe purposes.

<Problems to be Solved by the Invention> However, in such a time-controlled ignition timing control device, when the engine rotational speed increases due to acceleration etc., the engine rotational speed at the time of generation of the reference signal that measures the period of the reference signal and,
There will be a difference between the period of the reference signal and the engine rotational speed when calculating the time until the ignition timing.

In other words, the time from the conventional reference signal to the ignition timing is
It is calculated under the condition that the engine is in a steady state and the time required per unit crank revolution is constant, so when the engine is in an accelerating state, the ignition timing will shift to the retarded side. There is.

Therefore, afterburn, lack of power, misfire (discrepancy in ignition timing), and increase in CO and HC emissions.

Deterioration of fuel efficiency, misfire due to no fuel intake zone (
There was a problem in that a gap in injection timing occurred.

The present invention was made in view of such conventional circumstances,
An object of the present invention is to provide a time-controlled ignition timing control device that can predict a shift in ignition timing control timing due to an increase in engine rotation and control the ignition timing at the correct timing.

Means for Solving the Problems> Therefore, as shown in FIG. 1, the present invention includes: an operating state detection means for detecting an engine operating state including at least a throttle valve opening, an engine rotational speed, and a vehicle speed; basic ignition timing setting means for setting a basic ignition timing corresponding to a steady operating state as a crank angle position based on the engine operating state detected by the operating state detecting means; acceleration determination means for determining the acceleration state of the engine based on the acceleration state; and acceleration determination means for determining the acceleration state based on the acceleration determination means; basic ignition timing correction means during acceleration for adding and correcting the basic ignition timing by the angle minute; reference signal generating means for generating a reference signal at a predetermined crank angle position of the engine; and measuring the cycle of the reference signal each time the reference signal is generated. a reference signal period measuring means for measuring the period of the reference signal measured at the time of generation of the reference signal; The apparatus is configured to include: a time calculation means for calculating the time until the ignition timing; and an ignition signal output means for outputting an ignition signal to the ignition device at the ignition timing calculated by the time calculation means.

In the above configuration, when the acceleration state is determined, the advance angle determined according to the acceleration level determined by the acceleration level elements including the throttle valve opening, engine speed, and vehicle speed is set to the basic ignition timing. By performing the additive correction, it is possible to reduce the deviation in the output timing of the ignition control signal.

<Example> An embodiment of the present invention will be described below based on the drawings.

Referring to FIG. 2, 13 engine 1 includes an air cleaner 2° intake duct 3. Air is taken in via the throttle valve 4 and the intake manifold 5. The intake manifold 5 is provided with an electromagnetic fuel injection valve 6 for each cylinder, which injects fuel into the engine 1 that is pressure-fed from a fuel pump (not shown) and controlled to a predetermined pressure by a pressure regulator.

The fuel injection amount is controlled by a microcomputer built into the control unit 7 based on the engine rotation calculated based on the intake air flow rate Q detected by the air flow meter 8 and the period of the reference signal from the crank angle sensor 9. From the speed N, the basic fuel injection amount Tp = -Q/N
(K is a constant), correct this appropriately to determine the final fuel injection amount Ti = Tp - COEF + Ts (COEF is various correction coefficients, Ts is voltage correction), and drive with a pulse width of this Ti. This is done by outputting a pulse signal at a predetermined timing synchronized with engine rotation based on a reference signal from the crank angle sensor 9.

Each cylinder of the engine 1 is provided with an ignition plug 10, to which a high voltage generated by an ignition coil 11 is sequentially applied via a distributor 12, thereby igniting a spark to ignite and burn the air-fuel mixture. . Here, ignition coil 1
1 controls the timing of high voltage generation through a power transistor 13 attached thereto. Therefore, the ignition timing is controlled by controlling the on/off timing of the power transistor 13 using an ignition signal from the control unit 7.

Furthermore, the control unit 7 receives the throttle valve opening T from the throttle sensor 14 of the potentiometer 2 as a parameter of the engine operating state in order to control the ignition timing.
A detection signal of VO and a detection signal of vehicle speed VSP from vehicle speed sensor 15 are used.

Here, the crank angle sensor 9, the throttle sensor 14,
The vehicle speed sensor 15 corresponds to the driving state detection means, and the ignition plug 1
0, an ignition coil 11, and a distributor 12 constitute an ignition device.

C of the microcomputer in the control unit 7
In the PU, in the basic ignition timing setting routine shown in FIG. Based on the basic fuel injection amount Tp, the basic ignition timing (basic ignition advance) is determined by referring to the map.
ADV.

Search for. This routine is executed as a background job and corresponds to basic ignition timing setting means.

Then, the crank angle sensor 9 outputs an ignition signal at the ignition timing set in this way to cause ignition.
The ignition timing control routine shown in FIG. 4 is executed in synchronization with the reference signal from the engine.

Taking the case of a 4-cylinder engine as an example, the crank angle sensor 9 as a reference signal generating means has a crank angle of 180°.
100° before compression TDC in the compression stroke of each cylinder.
The reference signal REF is output.

When the reference signal REF is outputted from the crank angle sensor 9, the ignition timing control routine shown in FIG. Read the value of the counter 21 inside and use it as the reference signal I? The period of EF is measured as T+tEF, and the counter 21 is reset in the next step 2.

The steps 1 and 2 correspond to the reference signal period measuring means.

In step 3, the previous throttle valve opening T V OOLD is subtracted from the current throttle valve opening TvO to calculate the amount of change ΔTVO in the throttle valve opening. and,
In step 4, the amount of change ΔTVO in the throttle valve opening is compared with the acceleration determination value CACC. This part corresponds to the acceleration determining means.

Here, when the amount of change ΔTV○ in the throttle valve opening is equal to the acceleration judgment value cAcc, the process advances to step 5, and the basic ignition timing searched from the basic ignition timing setting routine number executed as the background job described above. (Basic ignition advance angle) Set ADVo as the final ignition advance angle ADV, proceed to step 6, and calculate the time T from the reference signal REF to the ignition timing using the following formula from the period TIEF and the ignition advance angle ADV. . This step 6 corresponds to the time calculation means.

T=T*tr・(100ADV)/180 Then, in step 7, this calculated time T is set in the conveyor register 22 in FIG. 5, and after the time T has elapsed from the reference signal REF, the coincidence in FIG. An ignition signal is output from the circuit 23 to cause ignition. This step 7 corresponds to the ignition signal output means.

On the other hand, in the determination in step 4, if the amount of change ΔTVO in the throttle valve opening is greater than or equal to the acceleration determination value CAee and it is determined that acceleration is occurring, the process proceeds to step 8.

In step 8, the detection signal of the throttle valve opening TVO from the throttle sensor 14 is read again, in step 9, the engine rotation speed N from the crank angle sensor 9 is read, and in step 10, the detection signal of the vehicle speed VSP from the vehicle speed sensor 15 is read. Load.

Then, in step 11, an acceleration level value ACC indicating the level at which the engine is being accelerated when the acceleration state is determined is calculated from acceleration levels such as throttle valve opening TVO, engine rotational speed N, and vehicle speed VSP. Calculate from the elements using the following formula.

ACC= (TVO/N-VSP) ・M However, M is an acceleration level coefficient.

Then, in step 12, the ignition timing advance GAcc when the engine accelerates is searched from the acceleration level value ACC by referring to a map, for example. That is, the functions of steps 8 to 12 correspond to basic ignition timing correction means during acceleration.

In step 13, the basic ignition timing (basic ignition advance angle) ADV retrieved by the basic ignition timing setting routine executed as the background job described above. Ignition advance angle ADV (
=AD Vo +GAcc) is the final ignition advance angle AD
V, the program proceeds to step 6, and calculates the time T until the corrected ignition timing from the period T□ and the ignition advance angle ADV.

In this way, when it is determined that the engine is in an accelerating state, the throttle valve opening TVO, the engine rotation speed N, and the vehicle speed V
Since the advance angle determined according to the acceleration level determined according to acceleration level elements such as SP is added to the basic ignition timing and corrected by X, it is possible to reduce the deviation in the output timing of the ignition control signal. becomes.

<Effects of the Invention> As explained above, according to the present invention, it is possible to time-control the ignition timing based on the latest rotation speed information, that is, the cycle of the latest reference signal, and also to correct deviations in control timing due to rotation fluctuations. This provides the advantage of being able to control the time by optimizing the control timing and preventing the occurrence of malfunctions.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the configuration of the present invention, Fig. 2 is a system diagram showing an embodiment of the invention, Fig. 3 is a flowchart of the basic ignition timing setting routine, and Fig. 4 is a flowchart of the ignition timing control routine. , FIG. 5 is a circuit diagram of the ignition signal output circuit. 1... Engine 6... Fuel injection valve 7... Control flow unit 8... Air flow meter
9... Crank angle sensor 10... Spark plug 1
1... Ignition coil 12... Distributor 13... Power transistor

Claims (1)

[Scope of Claims] Operating state detection means for detecting an engine operating state including at least a throttle valve opening, an engine rotational speed, and a vehicle speed; and a crank angle position based on the engine operating state detected by the operating state detection means. basic ignition timing setting means for setting basic ignition timing corresponding to a steady operating state; acceleration determining means for determining an acceleration state of the engine based on the engine operating state detected by the operating state detecting means; Acceleration basic ignition timing correction means for adding and correcting an advance angle determined according to an acceleration level determined by acceleration level elements including a throttle valve opening, an engine rotation speed, and a vehicle speed to the basic ignition timing when determining an acceleration state; , a reference signal generating means for generating a reference signal at a predetermined crank angle position of the engine; a reference signal period measuring means for measuring the period of the reference signal each time the reference signal is generated; time calculation means for calculating the time from the reference signal to the ignition timing set by the basic ignition timing setting means or corrected by the acceleration basic ignition timing correction means based on the cycle; 1. An ignition timing control device for an internal combustion engine, comprising: ignition signal output means for outputting an ignition signal to an ignition device at the determined ignition timing.