JPH079169B2 - Internal combustion engine controller - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal combustion engine control device which prevents an engine from overspeeding by an external signal.

[Conventional technology]

FIG. 2 shows a conventional device, 1 is a generator coil of a magnet generator, 2 and 3 are diodes for rectifying the output of the generator coil 1,
4 is a capacitor, 5 is an ignition coil, 6 is a spark plug, 7
Is a thyristor, 8 and 9 are rectifying diodes, 10 is a capacitor, 11 is a zener diode, 12 is a constant voltage source, 13 is an oil level switch that detects the oil level of the engine, and 14 is a signal coil of a magnet generator. An ignition signal is generated at the ignition timing. Reference numeral 15 is a rotation speed detection circuit to which the outputs of the oil level switch 13 and the signal coil 14 are input, and 16 is a thyristor.

Next, the operation of the above conventional device will be described. The output of the magneto coil 1 is rectified by the diode 3 and charged in the capacitor 4. On the other hand, when an ignition signal is input to the gate of the thyristor 7, the thyristor 7 becomes conductive, the charge of the capacitor 4 is discharged through the primary side of the ignition coil 5, and a high voltage is generated on the secondary side of the ignition coil 5. To do. This allows
The spark plug 6 discharges and ignites the engine. The output of the generator coil 1 is rectified by the diode 9 and
The voltage is smoothed by 10, and is made a constant voltage by a Zener diode 11, and a constant voltage source 12 is formed.

The oil level switch 13 is normally in the open state, and the rotation speed detection circuit 15 does not output. For this reason, the thyristor 16
Is off and the engine is ignited normally. However, when the oil level of the engine decreases, the oil level switch 13 closes, and at this time, the rotation speed detection circuit 15 that receives the output of the signal coil 14 that generates a signal proportional to the engine speed changes the engine speed. Outputs when the value exceeds a certain value,
Turn on thyristor 16. Therefore, the output of the magneto coil 1 is short-circuited by the thyristor 16 and ignition is not performed,
Excessive rotation is prevented and the engine is prevented from being worn or damaged due to overrun or the like.

[Problems to be solved by the invention]

However, in the above-mentioned conventional device, the oil level switch 13 is installed in the oil flow path of the engine,
Alternatively, when the oil pressure is detected, it is determined that the oil has decreased when the engine is stopped, although the oil has not decreased. Therefore, when the rotation speed increases immediately after the start, the rotation speed detection circuit 15 outputs an output,
There was a problem that the thyristor 16 was turned on and the over-rotation suppression control was performed, so that the engine could not operate normally even though the engine was normal.

The present invention has been made in order to solve the above problems, and normally performs the operation immediately after starting without performing over-rotation preventing control until the engine is warmed up after starting. An object of the present invention is to obtain an internal combustion engine control device capable of achieving the above.

[Means for solving problems]

The internal combustion engine control device according to the present invention is provided with the conduction preventing means for preventing conduction of the switching means for short-circuiting the output of the power generation coil until the engine temperature rises to a predetermined value after the engine is started.

[Action]

In the present invention, the conduction preventing means prevents conduction of the switching means after the engine has been started until the engine has been warmed up, during which the engine speed becomes equal to or higher than a predetermined value and the oil level switch operates to rotate the engine. Even if the number detecting means outputs an output, the switching means does not conduct, and the over-rotation preventing control is not performed.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. First
In the figure, 17 is a transistor, 18 is a comparator, and 19
22 is a resistor, and 23 is a thermistor attached to the engine to detect the engine temperature. Other configurations are the same as the conventional one.

In the above structure, when the spark plug 5 is ignited based on the output of the magneto coil 1, the oil level switch 13 operates and the engine speed becomes equal to or higher than a predetermined value, the speed detection circuit 15 outputs an output, and the thyristor 16 operates. When turned on, the output of the magneto coil 1 is short-circuited, and over-rotation suppression control is performed. On the other hand, a voltage obtained by dividing the voltage of the constant voltage source 12 by the resistors 21 and 22 is applied to the (−) terminal of the comparator 18, and a voltage divided by the resistor 20 and the thermistor 23 is applied to the (+) terminal. To be done. Therefore, the voltage of the (+) terminal exceeds the voltage of the (-) terminal for a predetermined time after the engine is started, the output of the comparator 18 is at a high level, and the transistor 17 is turned on. Therefore, the gate voltage of the thyristor 16 becomes zero, the thyristor 16 does not turn on even if the rotation speed detection circuit 15 outputs, and the engine is ignited as usual. The resistance value of the thermistor 23 decreases (+) after a lapse of a predetermined time after starting.
Since the voltage applied to the terminal decreases, the output of the comparator 18 becomes low level and the transistor 17 turns off. Therefore, the thyristor 16 is turned on by the output of the rotation speed detection circuit 15, and the overspeed suppression control is performed.

〔The invention's effect〕

As described above, according to the present invention, the switching means for short-circuiting the output of the generator coil is not conducted until the engine temperature rises to a predetermined value after the engine is started, and during this period, the oil level switch malfunctions. Also, the ignition of the engine is normally performed, and the operation immediately after the start can be normally performed.

[Brief description of drawings]

FIG. 1 is a circuit diagram of the device of the present invention, and FIG. 2 is a circuit diagram of a conventional device. 1 ... Generator coil, 4 ... Capacitor, 5 ... Ignition coil, 7,16 ... Thyristor, 13 ... Oil level switch, 15 ... Rotation speed detection circuit, 17 ... Transistor, 18 ...
… Comparator, 23 …… Thermistor. The same reference numerals in the drawings indicate the same or corresponding parts.

Claims (1)

[Claims] Claim: What is claimed is: 1. An ignition circuit for controlling energization from a power-generating coil to an ignition coil, a switching means for short-circuiting the output of the power-generating coil, an oil that operates when the oil level of an engine is detected and does not reach a predetermined value. In an internal combustion engine control device having a level switch, an engine speed detecting means for outputting an output when the engine speed is equal to or higher than a predetermined value and for operating the oil level switch, and conducting the switching means, an engine temperature detecting means for detecting the temperature of the engine, An internal combustion engine control device comprising a conduction preventing means for preventing conduction of the switching means until the engine temperature rises to a predetermined value after the engine is started.