JPH0754746A - Electronic control device for internal combustion engine - Google Patents

Abstract

PURPOSE:To provide a regular engine output and to prevent an engine from its damage by checking an electromagnetic pick up for whether it is properly wired or not, and correcting an ignition angle when reversely connected. CONSTITUTION:Whether an electromagnetic pick up is properly wired or not is judged in a CPU9 based on a pick up signal output from a waveform shaping circuit 3, to correct an ignition angle by the CPU9 when the electromagnetic pick up 2 is judged to be reversely connected, and by controlling ignition coil driving circuits 5A, 5B based on this correction, a proper ignition output position is always provided relating to spark plugs 7A, 7B.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic control unit for an internal combustion engine, which controls the operating state of the internal combustion engine according to ignition control of the internal combustion engine.

[0002]

2. Description of the Related Art FIG. 5 is a block diagram showing the structure of a conventional engine ignition control device. As an example, motorcycle V
The case where ignition control of a 90-degree engine is performed is shown. In the figure, 1 is 8 at 30 degree intervals based on a certain point on the circumference.
Convex part 1 that is formed at one place at 120 degree intervals in the opposite direction
It is a rotating body having a and rotating coaxially with a crankshaft of an engine (not shown). 2 detects the crank angle by detecting the convex portion 1a formed on the circumference of the rotating body 1,
An electromagnetic pickup that outputs a pickup signal. A waveform shaping circuit (PC) 3 shapes the waveform of the pickup signal and outputs a CPU interrupt request signal. A CPU 4 controls the ignition of the engine by calculating the ignition angle based on the CPU interrupt request signal. 5A and 5B are ignition coil drive circuits, 6A and 6B are ignition coils, and 7A and 7B are spark plugs. 8 is a waveform shaping circuit (PC) 3, CPU 4, ignition coil drive circuits 5A and 5
It is an electronic control unit composed of B. The electromagnetic pickup 2 and the ignition coils 6A and 6B are connected to the electronic control unit 8.

Next, the operation of the engine ignition control with the above-mentioned configuration when the electromagnetic pickup is normally connected will be described. First, when the rotating body 1 is rotated by the rotation of a crank shaft (not shown), the electromagnetic pickup 2 outputs the pickup signal shown in FIG. 6 by the convex portion 1a of the rotating body 1. The pickup signal is waveform-shaped by the waveform shaping circuit 3 and output to the CPU 4. FIG. 3 shows the waveform shaping circuit, and FIG. 6 shows the shaped CPU interrupt request signal waveform.

The CPU 4 executes the interrupt program in synchronism with the falling edge E of the waveform of the CPU interrupt request signal, which is output after the waveform is shaped by the waveform shaping circuit 3, and each time the interrupt program is executed, a number ( Choreograph the stage). (Processes by this interrupt program are called stage 1 interrupt to stage 9 interrupt, and the above-mentioned number makes one cycle for one engine revolution.)

Further, the CPU 4 uses the main program shown in FIG.
The ignition data is calculated according to the procedure shown in. That is, the engine speed NE is calculated from the pickup signal (S
1), the current angle of the crankshaft is obtained from the pickup signal (S2), and the engine speed NE obtained in S1
Then, the ignition angle is calculated from the ignition angle table shown in FIG. 7 (S3), and as shown in FIG. 6 when the electromagnetic pickup is normally connected, the stage for starting the ignition timer is placed before the ignition output position calculated from the ignition angle. And the stage closest to the ignition output position (S4), S1
The deviation from the head of the stage that starts the ignition timer to the ignition output position is determined as the ignition data from the engine speed NE obtained in step S5.

Then, it is judged whether or not the choreographed number and the number (ignition stage) for starting the ignition timer of each IGN, obtained in S5, match, and if they match, the main program The ignition data obtained by the calculation process of is set in the ignition timer, and an ignition output signal is generated at the set time.

[0007]

However, in the apparatus having the above structure, when the wiring of the electromagnetic pickup 2 is mistakenly connected in reverse, the pickup signal and the interrupt request signal waveforms are the electromagnetic pickup reverse connection in FIG. As shown at times,
Unlike the waveform at the time of normal connection, the position of the falling E is displaced from the normal case (shifted by T _{Z in} FIG. 6).
Therefore, there is a problem that the optimum ignition output position set for each engine of a different model is deviated, a normal engine output cannot be obtained, and in the worst case, the engine may be damaged.

According to the present invention, when the wiring of the electromagnetic pickup 2 is erroneously connected as described above, the ignition output position is displaced, a normal engine output cannot be obtained, and in the worst case, the engine may be damaged. In order to eliminate the problem that the electromagnetic pickup is wired correctly, a function to judge whether the electromagnetic pickup is wired correctly is provided.When the electromagnetic pickup is reversely connected, the ignition data is corrected to obtain the correct ignition output position. The purpose is to provide an excellent device that always obtains a regular engine output and prevents engine damage.

[0009]

In order to solve the above problems, the present invention uses the ignition angle table to determine the ignition angle based on the engine speed NE, and determines the ignition output position of the internal combustion engine according to the ignition angle. In the electronic control unit for an internal combustion engine to be controlled, a means for judging whether or not the connection of the electromagnetic pickup is correct, and a means for correcting the ignition angle when the electromagnetic pickup is reversely connected are provided to always provide a correct ignition output position. It has a configuration with functions.

[0010]

According to the present invention, it is determined whether the wiring of the electromagnetic pickup is normal connection or reverse connection, and the ignition angle table is selected depending on whether the connection is normal connection or reverse connection.
Since the correct ignition output position can always be obtained, the normal engine output can always be obtained, and the engine damage due to the shift of the ignition output position can be prevented.

[0011]

1 is a block diagram showing the configuration of an embodiment of an electronic control unit for an internal combustion engine according to the present invention. As an example, a case where V90 engine ignition control of a motorcycle is performed is shown. In the figure, 1 is the circumference of the circle, and 30 is based on a certain point.
It is a rotating body that has 8 convex portions 1a formed at 120 degree intervals in the opposite direction and 1 convex portion 1a in the opposite direction and rotates coaxially with the crank shaft of an engine (not shown). Reference numeral 2 is an electromagnetic pickup that detects a crank angle by detecting a convex portion 1a formed on the circumference of the rotating body 1 and outputs a pickup signal. A waveform shaping circuit (PC) 3 shapes the waveform of the pickup signal and outputs a CPU interrupt request signal. Reference numeral 9 calculates the ignition angle based on the CPU interrupt request signal, and judges whether the wiring of the electromagnetic pickup is normal (normal connection or reverse connection) when controlling the ignition of the engine. The CPU corrects the ignition data when the reverse connection is determined. 5A and 5B are ignition coil drive circuits, 6A and 6B are ignition coils, and 7A and 7B are spark plugs. 8 is a waveform shaping circuit (PC) 3, CPU 4, ignition coil drive circuits 5A and 5
It is an electronic control unit composed of B. The electromagnetic pickup 2 and the ignition coils 6A and 6B are connected to the electronic control unit 8.

Next, the operation of the engine ignition control device having the above structure will be described. First, when the rotating body 1 rotates due to the rotation of a crank shaft (not shown), the electromagnetic pickup 2
Outputs the pickup signal shown in FIG. 2 by the convex portion 1a of the rotating body 1. This pickup signal is waveform-shaped by the waveform shaping circuit 3 and output to the CPU 9. FIG. 3 shows the waveform shaping circuit, and FIG. 2 shows the shaped CPU interrupt request signal waveform.

The CPU 9 executes the interrupt program in synchronization with the falling edge E of the waveform of the CPU interrupt request signal, which is output after the waveform is shaped by the waveform shaping circuit 3, and each time the interrupt program is executed, a number (stage ) Choreography. (Processes by this interrupt program are called stage 1 interrupt to stage 9 interrupt, and the above-mentioned number makes one cycle for one revolution of the engine.)

Further, the CPU 9 executes the main program shown in FIG.
Ignition data is calculated by the procedure shown in. That is, S1
The engine speed NE is calculated from the pickup signal with
The current angle of the crankshaft is obtained from the pickup signal in 2 and the engine speed NE obtained in S1 in S3.
Then, the ignition angle is calculated from the fire angle table at the time of normal connection of the electromagnetic pickup or the fire angle table at the time of normal connection of the electromagnetic pickup shown in FIG. As shown in the connection or the electromagnetic pickup reverse connection, the stage for starting the ignition timer is set to a stage before the ignition output position calculated from the ignition angle and closest to the ignition output position. From the engine speed NE obtained in S1, the deviation from the head of the stage that starts the ignition timer to the ignition output position is determined as ignition data.

Then, it is judged whether or not the choreographed number and the number (ignition stage) for starting the ignition timer of each IGN obtained in S4 match, and if they match, the main program The ignition data obtained in the calculation process (S5) is set in the ignition timer, and an ignition output signal is generated at the set time.

Which of the two, the electromagnetic pickup normally connected firing angle table and the electromagnetic pickup reversely connected firing angle table, shown in FIG. 4, used to calculate the ignition angle is used. The determination procedure (the processing procedure of the CPU 9) will be described.

First, the main program calculates the time between the input signals when the interrupt program is reached by the trailing edge E of the waveform B, and measures the time (hereinafter referred to as TS) for each stage. For example, in FIG. 2, TS1 is the time from the stage 1 interrupt to the stage 2 interrupt. Then, the main program is once every engine revolution,
The calculation of Equation 1 is performed using the TS1 to TS3. As a result, when the formula 1 is satisfied 10 times or more consecutively, it is determined that the electromagnetic pickup is reversely connected, and a flag (hereinafter, referred to as F1) indicating a normal connection / reverse connection state of the electromagnetic pickup is set to 1. When the connection is normal, that is, when the expression 1 is not satisfied 10 times or more in a row and when the expression 2 is satisfied, it is determined that the electromagnetic pickup is normally connected, and this flag is set to 0. (However, F1 is set to 0 at the initial of the main program.) Formula 1 TS1 / TS2-TS2 / TS3> R1 Formula 2 TS1 / TS2-TS2 / TS3 <R2 (R1 and R2 are acceleration / deceleration of the engine. Time TS1, TS
2, constants set in advance in the data area of the program in consideration of slight variations in TS3).
It is determined which one of the ignition angle table of the electromagnetic pickup normally connected and the ignition angle table of the electromagnetic pickup reverse connection is used. Further, the main program has information in F1 as to whether the electromagnetic pickup is normally connected or reversely connected.

As shown in FIG. 4, two types of ignition angle tables are prepared in advance, one for normal connection of the electromagnetic pickup (for F1 = 0) and one for reverse connection of the electromagnetic pickup (for F1 = 1). The main program properly uses the table used for the calculation depending on the state of F1. Further, the waveform shift TZ in the normal connection and the reverse connection in FIG. 2 depends on the engine speed NE, and the reverse connection ignition angle table is the normal connection ignition angle table for each NE. It is corrected in advance by subtracting TZ of. This makes it possible to set the same ignition output position, although the required stage and the ignition data for starting the ignition timer are different between the normal connection and the reverse connection of the electromagnetic pickup.

By the way, in the stage 1, a difference occurs in the falling edge E of the CPU interrupt request signal due to the difference between the normal connection and the reverse connection of the electromagnetic pickup. Therefore, T
Since the value of Z is different from the value of TZ at the time of other stages, stage 1 cannot be designated as the stage for starting the ignition timer. This can be solved by setting the mounting angle of the rotating body 2 with respect to the engine top dead center so that the stage 1 does not become the stage for starting the ignition timer. FIG. 2 shows an example thereof, and according to this setting, the ignition control range (range in which the ignition output position can be taken) does not affect TS1.

[0020]

According to the above-mentioned method, if the connection of the electromagnetic pickup is confirmed to be correct and the connection is reversed, the ignition stage and the ignition data are determined based on the corrected ignition angle table. As a result, the correct ignition output position can be always provided regardless of the normal connection / reverse connection of the electromagnetic pickup, the normal engine output can be obtained, and the engine damage can be prevented.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an electronic control unit for an internal combustion engine according to the present invention.

FIG. 2 is a diagram showing an ignition output position of the present invention.

FIG. 3 is a diagram illustrating a waveform shaping circuit.

FIG. 4 is an ignition angle table used in the present invention.

FIG. 5 is a block diagram showing a configuration of a conventional electronic control unit for an internal combustion engine.

FIG. 6 is a diagram showing an ignition output position according to a conventional technique.

FIG. 7 is an ignition angle table used in the prior art.

FIG. 8 is a flowchart showing a procedure for determining ignition data.

[Explanation of symbols]

 1 Rotating Body 2 Electromagnetic Pickup 3 Waveform Shaping Circuit 4 CPU 5A Ignition Coil Drive Circuit 5B Ignition Coil Drive Circuit 6A Ignition Coil 6B Ignition Coil 7A Spark Plug 7B Spark Plug 8 Electronic Control Device

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location F02P 7/067 303 DG 01M 15/00 Z 7324-2G

Claims (1)

[Claims] 1. An electronic control unit for an internal combustion engine, wherein an ignition angle table is used to determine an ignition angle based on an engine speed, and an ignition output position of the internal combustion engine is controlled according to the ignition angle. A means for judging whether it is correct, a means for correcting the ignition angle by the judgment means when the electromagnetic pickup is not connected, and a means for always providing a correct ignition output position by the correction means. An electronic control unit for an internal combustion engine, characterized by: