JPH0355821Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to an internal combustion engine control device that prevents over-speeding of the engine using an external signal.

[Conventional technology]

Fig. 2 shows a conventional device, in which 1 is a generating coil of a magnet generator, 2 and 3 are diodes for rectifying the output of the generating coil 1, 4 is a capacitor, 5 is an ignition coil, 6 is a spark plug, 7 is a thyristor, 8 and 9 are rectifier 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 for the magnet generator, which controls the ignition timing of the engine. Generates an ignition signal. 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-described conventional device will be explained. The output of the generator coil 1 is rectified by a diode 3 and charged into a capacitor 4. On the other hand, when the ignition signal is input to the gate of the thyristor 7, the thyristor 7 becomes conductive, and the charge in the capacitor 4 is discharged through the primary side of the ignition coil 5, generating a high voltage on the secondary side of the ignition coil 5. do. This causes the spark plug 6 to discharge and ignite the engine. Further, the output of the generator coil 1 is rectified by a diode 9, smoothed by a capacitor 10, and made into a constant voltage by a Zener diode 11, thereby forming a constant voltage source 12.

The oil level switch 13 is normally in an open state, and the rotation speed detection circuit 15 does not output an output. Therefore, the thyristor 16 is in an off state, and the engine is ignited normally. However, when the engine oil level decreases, the oil level switch 13
is closed, and at this time, the rotation speed detection circuit 15, which receives the output of the signal coil 14 which generates a signal proportional to the engine rotation speed, outputs an output when the engine rotation speed exceeds a predetermined value, turning on the thyristor 16. Therefore, the output of the generator coil 1 is short-circuited by the thyristor 16, ignition is not performed, over-speeding is prevented, and the engine is prevented from being worn out or damaged due to overrun or the like.

[Problem that the invention attempts to solve]

However, in the conventional device described above, if the engine remains stopped for a predetermined period of time, the oil will completely fall into the oil reservoir and the lubricated parts will be starved of oil. Doing so may cause abnormal wear on the engine and shorten its lifespan.

This invention was made to solve the above-mentioned problems, and its purpose is to prevent abnormal wear of the engine due to lack of oil during startup.

[Means for solving problems]

The internal combustion engine control device according to this invention is provided with an engine temperature detection means for detecting the engine temperature, and a forced operation means for forcibly operating the oil level switch until the engine temperature reaches a predetermined value after the engine is started. It is.

[Effect]

In this invention, the oil level switch is forcibly operated by the forced operation means until the engine temperature rises to a predetermined value after the engine has started, and when the engine speed reaches a predetermined value or higher immediately after engine startup, the rotation speed detection means The switching means is turned on by the output of , and over-speed prevention control is performed.

〔Example〕

Examples of this invention will be described below with reference to the drawings. In FIG. 1, 17 is a transistor connected in parallel with the oil level switch 13, 18 is a comparator whose output is connected to the base of transistor 17, 19 to 22 are resistors, and 23 is a thermistor for detecting engine temperature. The other configurations are the same as before.

In the above configuration, the spark plug 5 is ignited based on the output of the generator coil 1, and when the oil level switch 13 is operated and the engine speed exceeds a predetermined value, the rotation speed detection circuit 15 outputs an output, and the thyristor 16 is activated. When turned on, the output of the generator coil 1 is short-circuited, and over-rotation prevention control is performed. On the other hand, a voltage obtained by dividing the voltage of the constant voltage source 12 by a resistor 20 and a thermistor 23 is applied to the (+) terminal of the comparator 18, and a voltage obtained by dividing the voltage by resistors 21 and 22 is applied to the (-) terminal. be done. Therefore, immediately after the engine starts, the engine temperature is low, so the thermistor 23
has a high resistance value, the voltage at the (+) terminal exceeds the voltage at the (-) terminal, the output of the comparator 18 is at a high level, and the transistor 17 is turned on. Therefore, the oil level switch 13 is turned on, and when the engine speed exceeds a predetermined value, the thyristor 16 is activated by the output of the speed detection circuit 15.
conducts, and overspeed prevention control is performed. Further, when the engine is warmed up and the temperature rises, the resistance value of the thermistor 23 decreases, and the output of the comparator 18 becomes low level. Therefore, over-speed prevention control is not performed unless the capacitor 17 is turned off and the oil level switch 13 is turned on.

[Effect of idea]

As described above, according to this invention, the oil level switch is forcibly turned on after the engine starts until the engine temperature reaches a predetermined value to enable overspeed prevention control, and the oil lubrication immediately after the engine starts is insufficient. During this period, over-speeding can be prevented and abnormal wear of the engine can be prevented, extending the life of the engine.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of this invented device, and FIG. 2 is a circuit diagram of a conventional device. 1...Generating coil, 4...Capacitor, 5...
Ignition coil, 7, 16... Thyristor, 13...
Oil level switch, 15... Rotation speed detection circuit, 17... Transistor, 18... Comparator, 23... Thermistor. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] An ignition circuit that controls power supply from the generator coil to the ignition coil, a switching device that short-circuits the output of the generator coil, an oil level switch that detects the oil level in the engine and operates if the oil level does not reach a predetermined value, and engine rotation. In an internal combustion engine control device, the engine temperature detection means detects the engine temperature, and the engine temperature detection means detects the engine temperature after the engine is started. 1. An internal combustion engine control device, comprising a forced operating means for forcing an oil level switch into an operating state until a predetermined value is reached.