Method and apparatus for manufacturing light metal alloy

An injection molding system for producing a metal alloy, comprising:

• an accumulation chamber which stores therein the metal alloy in a thixotropic state, said chamber having a first port, a second port through which the metal alloy in the thixotropic state is injected, and a third port, the first port being located between the second and third ports;
• a barrel which feeds said accumulation chamber through the first port with the metal alloy in the thixotropic state, said barrel positioned to gravity feed said metal alloy to said accumulation chamber;
• a piston-cylinder assembly having a piston and a cylinder, the cylinder housing the piston and being connected to the third port, wherein movement of said piston outwardly from said cylinder produces suction pressure in the accumulation chamber for drawing said metal alloy in the thixotropic state into said accumulation chamber from said barrel, and movement of said piston inwardly into said cylinder produces pressure for injecting said metal alloy in the thixotropic state from said accumulation chamber into a mold;
• and
• a valve disposed between said barrel and said accumulation chamber, said valve selectively opening and closing said first port in response to one of (a) a pressure differential between said accumulation chamber and said barrel caused by movement of said piston, and (b) movement of said piston.

An apparatus for injecting metal alloy in a thixotropic state, comprising:

• (a) a barrel for converting the metal alloy from a liquid state into the thixotropic state;
• (b) a feeder supplying the barrel with the metal alloy in a liquid state;
• (c) a chamber connected to, but housed separately from, the barrel to receive the metal alloy in the thixotropic state;
• (d) a piston housed in a cylinder separated from the barrel and movable within the cylinder to draw the metal alloy in the thixotropic state into the chamber using suction pressure created by retraction of the piston and to inject the metal alloy in the thixotropic state from the chamber;
• and
• (e) a valve disposed between the barrel and the chamber and responsive to the movement of the piston,
• wherein the chamber comprises a first port through which the metal alloy in the thixotropic state is received, a second port through which the metal alloy in the thixotropic state is injected, and a third port connected to the cylinder housing the piston, the first port being located between the second and third ports.