JPH03213665A - Ignition timing control device - Google Patents

Abstract

PURPOSE:To keep on operating at the minimum by generating the first pulse signals by means of ignition signal coils, generating the second pulse signals by means of a crank angle sensor, and controlling ignition by another means when it is detected by the second pulse signals that the crank angle sensor is abnormal. CONSTITUTION:A device is equipped with the ignition coils 2 and 3 of No.1 and No.2 cylinder which generate the first pulse signals in response to specified crank angle positions while being synchronized with engine revolution, and with a crank angle sensor 1 which generates the second pulse signals each of which is higher in frequency that each first pulse signal, and has thereby output signals from these units inputted into a microcomputer 4. In the microcomputer 4, the crank angle is detected based on the first and the second pulse signals so that the ignition in an engine is thereby controlled. In addition, it is also detected whether or not the crank angle sensor 1 is abnormal based on the second pulse signals, and when the sensor is found abnormal, the ignition is controlled by another means such as time estimation or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION C. Industrial Application Field The present invention relates to an ignition timing control device for an internal combustion engine used, for example, in an outboard motor.

"Tsai Yu/Episode 7-1" Conventionally, the crank angle was detected by a crank angle sensor that generates signals at intervals of, for example, 1 degree, and ignition was controlled at the optimal angle for the engine based on the detected crank angle.

However, if the crank angle sensor becomes abnormal due to disconnection, short circuit, etc., the crank angle becomes unknown and ignition control becomes impossible, causing the engine to stop.

This was extremely inconvenient for outboard motors as they could not return to port.

[Problems to be Solved by the Invention] The conventional ignition timing control device as described above has a problem in that the engine will stop if the crank angle sensor becomes abnormal.

This invention was made to solve the above-mentioned problems, and an object of the present invention is to obtain an ignition timing control device that can control engine ignition even if the crank angle sensor is abnormal.6 [Solving the Problems] [means for]? /TXX1. Book I Yukinsu Old 7111 Layered Chopsticks 10
Enshita L - It is equipped with means to humble oneself.

(i) An ignition signal coil that is synchronized with engine rotation and generates a first pulse signal in response to a predetermined crank angle position.

(ii) A crank angle sensor that generates a second pulse signal that is synchronized with the rotation of the crank and has a higher frequency than the first pulse signal.

<iii), when the crank angle is detected based on the first and second pulse signals to perform ignition control of the engine, and an abnormality in the crank angle sensor is detected based on the second pulse signal; is a microcomputer that controls ignition by another means.

[Operation] In the present invention, the ignition signal coil generates a first pulse signal corresponding to a predetermined crank angle position.

Further, a second pulse signal is generated by the crank angle sensor in accordance with the crank angle.

Then, the microcomputer detects the crank angle corresponding to the optimum ignition timing based on the first and second pulse signals, and performs ignition control of the engine, and based on the second pulse signal, the crank angle corresponding to the optimum ignition timing is detected. If an abnormality in the crank angle sensor is detected, ignition control is performed by another means.

[Embodiment] The configurations of the first and second embodiments of the present invention are the same except for the microcomputer program, and will be described with reference to FIG.

FIG. 1 is a circuit diagram showing first and second embodiments of the present invention.

In FIG. 1, the first and second embodiments of the present invention include a crank angle sensor (1) and a first cylinder ignition signal coil (
2), the ignition signal coil (3) of the second cylinder, the crank angle sensor (1), the microcomputer (4) connected to the ignition signal coils (2) and (3), and the microcomputer (4) connected to this microcomputer (4). ignition coils (5) and (6).

Next, the operation of the first embodiment described above will be explained with reference to FIGS. 2 and 3.

FIG. 2 is a signal waveform diagram showing the operation of the first and second embodiments of the invention, and FIG. 3 is a flowchart showing the operation of the first embodiment of the invention.

First, the main program (not shown) registered in the microcomputer (4) is used to search the ignition timing map and control the injector, but since it normally has a long operating cycle (for example, 10m5), it is repeated in short cycles. Ignition timing control is handled by interrupt control to the main program.

That is, upon generation of a pulse signal from the ignition signal coil (2) or (3), the main program shifts to the ignition reference signal interrupt loop shown in FIG. 3(a).

In step (10), it is determined whether the value of the sensor abnormality counter is greater than or equal to a predetermined value n. If it is less than the predetermined value n, proceed to λyd (11), and if it is greater than the predetermined value n, proceed to step (14).

In Stella 2 (11), the value of the sensor abnormality counter is incremented by "1".

Load the count target value corresponding to the optimal ignition timing,
A target value for an ignition counter (not shown) is set.

In step (13), the ignition counter starts counting.

After that, other processes (over-speed prevention control, etc.) are executed and the process returns to the main screen.6 On the other hand, the ignition counter counts the pulse signal of the crank angle sensor (1), and when this count value reaches the target value, the third The process moves to the ignition processing loop shown in Figure (b), ignites the engine (step (20)), clears the sensor abnormality counter (step (21)), and then returns to the main process.

Here, if the crank angle sensor (1) is abnormal, the ignition counter will not reach the target value because it will not generate a pulse signal, and will not move to the ignition processing loop, so the sensor abnormality counter will be cleared. Nor. Therefore, a pulse signal is generated from the ignition signal coil (2) or (3), the ignition reference signal is calculated by WI, and when it becomes equal to or greater than a predetermined value (>n), the process moves to step (14).

In step (14), abnormal ignition processing is performed.

That is, for example, ignition control is performed based on time prediction. If we measure the period T of the pulse signal of the ignition signal coils (2) and (3) of the first and second cylinders and perform ignition control at a predetermined crank angle θ, then From the pulse signal of , ignition control is performed after T・θ/360" time has elapsed.For example, if θ-10°, ignition control is performed after T/36 time has elapsed.After that,
Perform other processing and return to main.

Here, when transitioning from normal ignition processing to abnormal ignition processing, a misfire state occurs temporarily, but this is only for a very short period of time and does not cause any problem in terms of engine operation.

Next, the operation of the second embodiment described above will be explained in FIGS. 2 and 4.
FIG. 4 is a flowchart showing the operation of the second embodiment of the present invention.

In the ignition timing control device that counts the pulse signal of the crank angle sensor (1) by an ignition counter and determines the ignition timing accordingly, in step (30),
The microcomputer (4) checks the value of the ignition counter at predetermined intervals. Determine whether the previous value and the current value are the same. If they are the same, proceed to step L:II (33); if they are different, proceed to step (31).

In step (31), the sensor abnormality counter is cleared.

In step (32), normal ignition processing similar to the first embodiment described above is performed. After that, return to Stella 2 (30).

In step (33), the sensor abnormality counter
Add 1”.

In step (34), it is determined whether the value of the sensor abnormality counter is greater than or equal to a predetermined value. If it is more than the predetermined value, proceed to Stella 2 (35), and if it is less than the predetermined value, proceed to Stellar 2 (35).

Proceed to step (32).

In step (35), the same abnormal ignition process as in the first embodiment described above is performed. After that, Stella 2 (3
Return to 0).

As described above, each embodiment of the present invention performs ignition processing that does not use the crank angle sensor (1), which is different from normal ignition processing when an abnormality is detected in the crank angle sensor (1). This has the effect of preventing the engine from stopping due to the abnormality (1). Therefore, for example, in the case of an outboard motor, even if the crank angle sensor is abnormal, the engine can still be operated and the motor can return to the port, greatly improving safety.

In addition, in each of the above embodiments, when the value of the sensor abnormality counter is equal to or higher than a predetermined value (for example, a value corresponding to 2 revolutions), the abnormal ignition process is performed because the crank angle sensor (1) has a simple contact failure. This means that temporary signal abnormalities due to such reasons are not considered abnormal.

Further, the predetermined time in the second embodiment is, for example, a fixed time of 5 m5 ec, or a random undefined time.

Furthermore, it goes without saying that even if two or more different types are repeated for a certain period of time, the intended purpose can be achieved.

Further, in the above embodiment, an example of time prediction is shown as a means of abnormal ignition processing, but other means, for example, when the pulse signal of the ignition signal coil (2) or (3) reaches a predetermined level, the engine It is also possible to set it to ignite.

Incidentally, in the above description, the case where the present invention is used in a two-cylinder engine has been described, but it goes without saying that it can also be used in other multi-cylinder engines.

[Effects of the Invention] As explained above, the present invention provides an ignition signal coil that is synchronized with the rotation of the engine and generates a first pulse signal in accordance with a predetermined crank angle position; A crank angle sensor that generates a second pulse signal having a higher frequency than the first pulse signal, and detects the crank angle based on the first and second pulse signals to control ignition of the engine. , and a microcomputer that controls ignition by another means when an abnormality in the crank angle sensor is detected based on the second pulse signal, so even if the crank angle sensor is abnormal, the engine can be stopped without stopping. It is possible to continue operation for a limited period of time, which improves the reliability of the engine and contributes to ensuring safety.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing the first and second embodiments of the present invention;
Fig. 2 is a signal waveform diagram showing the operation of each embodiment of the present invention, Fig. 3 is a flowchart showing the operation of the first embodiment of the invention, and Fig. 4 is an operation of the second embodiment of the invention. It is a flowchart figure which shows. In the figure, (1... crank angle sensor, (2... first cylinder ignition signal coil, (3...
2nd cylinder ignition signal coil, (4... microcomputer, (ch... ignition coil, (6)
... It's the ignition coil. In each figure, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] an ignition signal coil that synchronizes with the rotation of the engine and generates a first pulse signal according to a predetermined crank angle position; a second pulse signal that synchronizes with the rotation of the crank and has a higher frequency than the first pulse signal; ignition control of the engine by detecting the crank angle based on the crank angle sensor and the first and second pulse signals, and detecting an abnormality in the crank angle sensor based on the second pulse signal. An ignition timing control device characterized by comprising a microcomputer that controls ignition by another means when detecting the ignition timing.