Electromagnetic pump type automatic molten-metal supply apparatus

Abstract

When molten metal within a molten metal tank is supplied to an injection sleeve of a casting machine through a molten-metal supply pipe by the operation of an electromagnetic pump, a sensor detects changes in height of the surface of molten metal within the tank as time passes, and a controller corrects the period during which the pump is driven on the basis of molten-metal surface detection signals from the sensor. The controller divides the difference in height of the surface of molten metal within the tank as between its highest level and its lowest level into a number n of regions, and drives the pump in such a controlled manner that the pump is connected to a three phase AC power source and is intermittently supplied with three-phase power having a constant voltage and a constant frequency so that the pump controls the molten-metal supply amount with its driven period serving as a molten-metal supply period. A molten-metal supply period for each supply operation is calculated from a predetermined equation using a molten-metal supply period corresponding to the highest level of the molten metal surface which is in turn determined from the results of casting tests. The degree of precision at which molten metal is supplied is further enhanced by an improved structure of the molten-metal supply pipe.

Dependencies are inferred from the claim text.