Electrical servo driven rollover melt furnace

Abstract

An apparatus and method for melting metal and casting molds. The apparatus includes a rollover melt furnace having a crucible and a mold. The apparatus also includes an electrical servomotor that drives rotation of the crucible about an axis of rotation. This rotation of the crucible causes molten metal to flow from a pour opening in the crucible into a fill opening in the mold. The apparatus may further include a controller to carry out a pouring process in compliance with a pour profile and a melting process in compliance with a melt profile.

1 . An apparatus for melting metal and casting molds comprising:
 a rollover melt furnace comprising a rotating shaft and a crucible connected to the rotating shaft for rotation therewith, the crucible having an exterior surface that includes a pour opening; and   an electrical motor connected in driving relationship to the rotating shaft of the rollover melt furnace.   
   
   
       2 . The apparatus of  claim 1 , further comprising a motion feedback loop that controls the electrical motor, the motion feedback loop comprising a controller and a feedback device, wherein:
 the feedback device is capable of sending a plurality of feedback signals to the controller; and   the controller is capable of receiving the plurality of feedback signals from the feedback device, comparing the plurality of feedback signals to a pour profile, and sending a plurality of command signals to the electrical motor, the command signals comprising attempts to minimize a difference between the feedback signals and the pour profile.   
   
   
       3 . The apparatus of  claim 2 , wherein:
 the crucible has an actual position, an actual velocity, and an actual acceleration, about an axis of rotation; and   the plurality of feedback signals correspond to at least one of: the actual position of the crucible, the actual velocity of the crucible, and the actual acceleration of the crucible about said axis of rotation.   
   
   
       4 . The apparatus of  claim 2 , wherein the plurality of command signals correspond to at least one of: a velocity of the electrical motor and an acceleration of the electrical motor. 
   
   
       5 . The apparatus of  claim 1 , further comprising a temperature feedback loop that controls a temperature of the crucible. 
   
   
       6 . An apparatus for melting metal and casting molds comprising:
 a rollover melt furnace comprising a rotating shaft, a crucible connected to the rotating shaft for rotation therewith, the crucible having a pour opening into an interior cavity, and a mold having an exterior surface that includes a fill opening, the fill opening being sized to accommodate a flow from the pour opening of the crucible;   an electrical motor connected in driving relationship to the rotating shaft of the rollover melt furnace; and   a controller, the controller being capable of sending a plurality of command signals to the electrical motor.   
   
   
       7 . The apparatus of  claim 6 , further comprising a feedback device capable of sending a plurality of feedback signals to the controller. 
   
   
       8 . The apparatus of  claim 7 , wherein the feedback device is incorporated within the electrical motor. 
   
   
       9 . The apparatus of  claim 7 , wherein the feedback device is remotely mounted on the rollover melt furnace. 
   
   
       10 . The apparatus of  claim 7 , wherein:
 the crucible has an actual position, an actual velocity, and an actual acceleration, about an axis of rotation; and   the plurality of feedback signals correspond to at least one of: the actual position of the crucible, the actual velocity of the crucible, and the actual acceleration of the crucible about said axis of rotation.   
   
   
       11 . The apparatus of  claim 6 , wherein the plurality of command signals correspond to at least one of: a velocity of the electrical motor and an acceleration of the electrical motor. 
   
   
       12 . The apparatus of  claim 6 , further comprising at least one pour profile, the at least one pour profile representing a set time interval and at least one of: a set position of the crucible, a set velocity of the crucible, and a set acceleration of the crucible about an axis of rotation over the set time interval, wherein the controller is further capable of:
 storing the at least one pour profile;   receiving a user command;   accessing a desired pour profile based on the user command;   determining a command signal based on the desired pour profile; and   sending the command signal to the electrical motor.   
   
   
       13 . The apparatus of  claim 12 , wherein the controller is further capable of:
 receiving a plurality of feedback signals from a feedback device; and   comparing the desired pour profile with the plurality of feedback signals and determining a command signal therefrom, the command signal comprising an attempt to minimize a difference between the feedback signals and the desired pour profile.   
   
   
       14 . The apparatus of  claim 6 , wherein the controller is further capable of:
 storing and accessing at least one melt profile, the at least one melt profile representing a set time interval and a set temperature of the interior cavity of the crucible over the set time interval; and   sending a temperature command to the crucible.   
   
   
       15 . The apparatus of  claim 14 , wherein the controller is further capable of:
 receiving a plurality of temperature readings from a temperature feedback device; and   comparing the at least one melt profile with the plurality of temperature readings and determining the temperature command therefrom, the temperature command comprising an attempt to minimize a difference between the temperature readings and the at least one melt profile.   
   
   
       16 . A method of melting metal and casting molds in a rollover melt furnace comprising a rotating shaft and a crucible connected to the rotating shaft for rotation therewith, the crucible having a pour opening into an interior cavity, the pour opening being located on an exterior surface of the crucible, comprising the steps of:
 loading an ingot into the interior cavity of the crucible;   melting the ingot in the interior cavity of the crucible thereby forming a molten metal;   attaching a mold to the rollover melt furnace, the mold having an exterior surface that includes a fill opening, the fill opening being sized to accommodate a flow from the pour opening of the crucible; and   rotating the shaft using an electrical motor to transfer the molten metal from the crucible to the mold.   
   
   
       17 . The method of  claim 16 , further comprising the step of automatically positioning a clamp to receive the mold. 
   
   
       18 . The method of  claim 16 , wherein the step of melting the ingot comprises controlling a temperature of the crucible based on a melt profile. 
   
   
       19 . The method of  claim 16 , further comprising the steps of:
 rotating the shaft so that the crucible reaches a wet lip position; and   after reaching the wet lip position, rotating the shaft so that the crucible returns to the upright position before reaching an inverted position.   
   
   
       20 . The method of  claim 16 , wherein the step of rotating the shaft using an electrical motor comprises accelerating rotation of the shaft until the crucible reaches a set velocity. 
   
   
       21 . The method of  claim 16 , wherein the step of rotating the shaft using an electrical motor comprises:
 rotating the shaft so that the crucible reaches a fill position, in which molten metal flows from the crucible to the mold; and   after reaching the fill position, decelerating rotation of the shaft until the crucible reaches an inverted position.   
   
   
       22 . The method of  claim 16 , wherein the step of rotating the shaft using an electrical motor comprises controlling rotation of the shaft based on a pour profile. 
   
   
       23 . The method of  claim 16 , further comprising the step of inputting a command into a controller to automatically control rotation of the shaft.