PURPOSE: To prevent the ignition to fuel by the damage of an electrostatic oil filter, by automatically stopping the supply of a current when the rotation of an engine is lowered, stopped or abruptly reduced in its speed.
CONSTITUTION: An electronic control unit 3 calculates the number of rotations and acceleration of an engine upon the reception of the signal from a rotation detection sensor 2. That is, when the number of rotations of the engine exceeds the ON/OFF set number of rotations, a zero signal is issued to an inverter 8 and turns a relay 4 ON to be inputted to an electrostatic oil filter 5. When the number of rotations of the engine reaches a definite value or less, an 1 signal is outputted to the inverter 8 to turn the relay 4 OFF and the application to the electrostatic oil filter 5 is turned OFF. The electronic control unit 3 always calculate speed change per minute time and the 1 signal is outputted to the inverter 8 even when speed reducing acceleration exceeding the set acceleration is generated.
SHIBAKAWA TAKAHIRO
NOZAWA MASAE
NIPPON SOKEN