The bar feeding machine is a custom designed system complimenting the vertical continuous casting process.
The continuous casting process consists of a water-cooled die located at the bottom of a vessel into which molten metal is poured. The metal is cooled and solidifies adopting the shape of the die.
The solid profile from the die is slowly pulled vertically from beneath the vessel through the die, allowing fresh molten material to be cooled producing a solid ingot of material extruded beneath the machine.
Various die sizes, profiles and shapes may be produced forming bars of different lengths as required. Asymmetrical shapes and hollow tubes may also be produced.
The existing machinery consisted of two pairs of V shaped drive rollers forced together trapping the bar and pulling the material through the die. The design suffered from slipping of the drive through the rollers and limitations of the size of bar processed, demanding a larger more efficient system.
Other problems encountered were deformation of the bar as it was pulled using both pairs of rollers resulting in a bend along the length.
Taking the clients list of requirements and their experience we examined the problems so far encountered and developed a new design specially developed to provide a high degree of control and automation to the process.
The system uses two clamp assemblies to control the bar.
The upper clamp acts as a safety lock, preventing any movement of the bar, while a lower clamp grips the bar and moves vertically to pull the bar through the die.
Both clamps work in sequence with each other, such that one clamp always grips the bar at any one time. Both clamps feature 3 (or 4) radially arranged jaws to ensure concentricity.
The cutting system is suspended below the moving clamp and consists of two assemblies containing abrasive discs that traverse horizontally, cutting through the bar.
The automation of the design uses movement detection and surface recognition sensors that detect any skidding of the moving clamp against the bar - automatically increasing the clamping force.
Surface temperature monitoring measures the bar temperature as it passes through the top clamp. If the bar is not at the correct temperature, the system halts until the bar reaches the correct temperature preventing a melt through condition.
When sufficient material is produced, the bar is cut to the required length and allowed to fall into a water-filled cooling well, where it is manually removed using appropriate lifting equipment.
The cutting system uses two abrasive discs, triggered automatically when the programmed length has been produced. The discs traverse from both sides and are programmed to avoid a collision with the other. Disc wear monitors signal the operator that a disc change is required and the discs move to a service position.
The cutting and disk maintenance can be performed without stopping the process.
Automatic safety guards are provided which limit access during the process.
The control system uses a PLC sequence controller to monitor the hydraulic systems and includes a PC based programming interface.
© Production Designs Ltd 2002