CONTROL CIRCUIT FOR CONTROLLING ELECTROMAGNETIC VALVE USED FOR STOPPING OPERATION OF DIESEL ENGINE

摘要

PURPOSE:To prevent occurrence of accidental hazard, by stopping operation of engine positively, for instance, at the time when malfunctioning of a timing relay to the coil of an engine-stopping electromagnetic valve is caused, through employment of an arrangement that re-starting of engine is not permitted until engine speed becomes lower than a predetermined low speed. CONSTITUTION:When diesel engine is started, low-speed relay contact 9 operated at a sufficiently low speed is closed, so that auxiliary relay coil 10 is excited. Resultantly, one auxiliary relay contact 11 is opened whereas the other auxiliry relay contact 12 is closed. In this state (in operation of engine), if lockout relay contact 1 is closed by reason of some trouble caused in the engine or otherwise engine-stopping switch contact 2 is closed by engine stopping operation, coil 5 of an engine stopping contactor is excited via contact 12 and contacts 6, 7 of the engine stopping contactor are closed simultaneously. As the result, fuel supply is stopped by engine-stopping electromagnetic valve 8 and a coil (5) exciting circuit is self-sustained, so that re-starting of engine is disabled.