| 摘要 |
PURPOSE:To lower the running cost of a titled device and increase the degree of freedom for selection of the diameters of a base metal core by forming a crucible to an assembly type consisting separately of an outside cylinder and an inside cylinder, and providing a float which can move vertically in the space between the outside and inside cylinders. CONSTITUTION:Raw material for melting is charged into an assembly type crucible, and is melted with a heater 13. When molten metal 2 attains a prescribed temp., a lead bar 14 is inserted into the hole 12a of an inside cylinder 12 and a base metal core 1 is coupled directly to the buttom thereof. Next, a float 8 is loaded and is put into the molten metal 2 to force up the melt level in the crucible above the height of the cylinder 12, whereby a dip form part 15 enclosed by the inside surface of the float 8 and the top surface of the cylinder 12 is formed. Thence, the bar 14 is pulled up at a constant speed, and the molten metal 2 is solidified and stuck around the core 1, whereby a cast rod 4 is obtained. In the same manner as in conventional art, part of the rod 4 is roughly drawn, and the other part are recirculated as the core 1. The molten metal level is controlled with the float 8 like in conventional art. |
