Injection tip for casting machine, casting machine and method using such a tip

Abstract

Disclosed is an injection tip for injecting liquid metal under pressure, suitable for being inserted between a liquid metal supply conduit and an injection opening of a mould, the injection tip having a tubular in shape, made from electrically insulating refractory material and in that it includes a channel suitable for the flow of liquid metal between a first end referred to as the upstream end, suitable for being connected to the conduit, and a second end, referred to as the downstream end, suitable for being connected to the mould, and an electromagnetic coil, positioned between the ends, the axis of which merges with at least a portion of the axis of the channel. Also disclosed is a casting machine using such a tip and a method for casting metal using the machine.

1 - 10 . (canceled) 
     
     
         11 . Tip ( 20 ) for injecting liquid metal ( 13 ) under pressure, said tip being tubular in shape, made from electrically insulating refractory material, suitable for being inserted between a conduit ( 12 ) for supplying liquid metal and an injection opening ( 33 ) of a mould ( 30 ), said tip comprising an injection channel ( 22 ) suitable for the flow of liquid metal between a first end, named upstream end ( 23 ), suitable for being connected to said conduit and a second end, named downstream end ( 24 ), suitable for being connected to the mould, wherein:
 said tip comprises an electromagnetic coil ( 26 ) placed between said ends, having an axis merged with at least one axis portion of the channel, suitable for being supplied with a current pulse from a high-voltage generator ( 40 ) and generating an electromagnetic pinch in the injection channel ( 22 ),   the electromagnetic coil ( 26 ) is embedded in the material of the tip.   
     
     
         12 . Tip according to  claim 11 , wherein the injection channel ( 22 ) has a diameter comprising a narrowing ( 27 ) between the upstream end ( 23 ) and the electromagnetic coil ( 26 ). 
     
     
         13 . Tip according to  claim 11 , wherein the electromagnetic coil ( 26 ) is a multi-turn coil. 
     
     
         14 . Tip according to  claim 11 , wherein the electromagnetic coil ( 26 ) is a single-turn coil. 
     
     
         15 . Casting machine ( 10 ) comprising a liquid metal reservoir ( 11 ), a conduit ( 12 ) for the supply of liquid metal connected to said reservoir and fitted with an electromagnetic pump ( 50 ) suitable for causing the liquid metal to flow in said conduit in the direction of a mould ( 30 ), wherein the machine comprises a tip ( 20 ) according to  claim 11  between said conduit and an injection opening ( 33 ) of said mould. 
     
     
         16 . Machine according to  claim 15 , wherein the electromagnetic pump ( 50 ) comprises a plurality of induction coils ( 51 ) which are coaxial to the conduit ( 12 ) for supplying liquid metal and which are suitable for induction heating of the metal flowing in said conduit. 
     
     
         17 . Machine according to  claim 16 , wherein the induction coils ( 51 ) are supplied with polyphase current so as to generate a moving magnetic field and to drive the liquid metal in the direction of the tip ( 20 ). 
     
     
         18 . Machine according to  claim 16 , wherein a device ( 52 ) for cooling the induction coils ( 50 ) is interposed between said coils and the conduit ( 12 ). 
     
     
         19 . Method for casting liquid metal under pressure in a metal mould ( 30 ), wherein:
 a casting machine ( 10 ) is used which comprises a liquid metal reservoir ( 11 ), a conduit ( 12 ) for supplying liquid metal, which is connected to said reservoir and fitted with an electromagnetic pump ( 50 ) suitable for causing the liquid metal to flow in said conduit in the direction of a mould ( 30 ),   the electromagnetic pump ( 50 ) is supplied with a polyphase current so as to displace the liquid metal from the reservoir to the injection opening of the mould,   
       wherein the casting machine ( 10 ) comprises a tip ( 20 ) comprising an electromagnetic coil ( 26 ) surrounding an injection channel ( 22 ) between said conduit and an injection opening ( 33 ) of said mould and in that, at the end of injection, the electromagnetic coil ( 26 ) of the tip ( 20 ) is supplied with an electric current pulse from a high-voltage generator ( 40 ) in order to generate an electromagnetic pinch in the injection channel ( 22 ) and to propel the liquid metal under pressure towards the injection opening ( 33 ) of the mould. 
     
     
         20 . Tip according to  claim 12 , wherein the electromagnetic coil ( 26 ) is a multi-turn coil. 
     
     
         21 . Tip according to  claim 12 , wherein the electromagnetic coil ( 26 ) is a single-turn coil. 
     
     
         22 . Casting machine ( 10 ) comprising a liquid metal reservoir ( 11 ), a conduit ( 12 ) for the supply of liquid metal connected to said reservoir and fitted with an electromagnetic pump ( 50 ) suitable for causing the liquid metal to flow in said conduit in the direction of a mould ( 30 ), wherein the machine comprises a tip ( 20 ) according to  claim 12  between said conduit and an injection opening ( 33 ) of said mould. 
     
     
         23 . Casting machine ( 10 ) comprising a liquid metal reservoir ( 11 ), a conduit ( 12 ) for the supply of liquid metal connected to said reservoir and fitted with an electromagnetic pump ( 50 ) suitable for causing the liquid metal to flow in said conduit in the direction of a mould ( 30 ), wherein the machine comprises a tip ( 20 ) according to  claim 13  between said conduit and an injection opening ( 33 ) of said mould. 
     
     
         24 . Casting machine ( 10 ) comprising a liquid metal reservoir ( 11 ), a conduit ( 12 ) for the supply of liquid metal connected to said reservoir and fitted with an electromagnetic pump ( 50 ) suitable for causing the liquid metal to flow in said conduit in the direction of a mould ( 30 ), wherein the machine comprises a tip ( 20 ) according to  claim 14  between said conduit and an injection opening ( 33 ) of said mould. 
     
     
         25 . Casting machine ( 10 ) comprising a liquid metal reservoir ( 11 ), a conduit ( 12 ) for the supply of liquid metal connected to said reservoir and fitted with an electromagnetic pump ( 50 ) suitable for causing the liquid metal to flow in said conduit in the direction of a mould ( 30 ), wherein the machine comprises a tip ( 20 ) according to  claim 15  between said conduit and an injection opening ( 33 ) of said mould. 
     
     
         26 . Casting machine ( 10 ) comprising a liquid metal reservoir ( 11 ), a conduit ( 12 ) for the supply of liquid metal connected to said reservoir and fitted with an electromagnetic pump ( 50 ) suitable for causing the liquid metal to flow in said conduit in the direction of a mould ( 30 ), wherein the machine comprises a tip ( 20 ) according to  claim 16  between said conduit and an injection opening ( 33 ) of said mould. 
     
     
         27 . Machine according to  claim 16 , wherein a device ( 52 ) for cooling the induction coils ( 50 ) is interposed between said coils and the conduit ( 12 ).