초록 ▼

An electromagnetic valve for use for discharge of molten metal from a container, comprises a main body providing a discharge passage through which, in use, molten metal will flow; and electrical induction coil located about the passage; means to supply an alternating electric current to the coil whe

An electromagnetic valve for use for discharge of molten metal from a container, comprises a main body providing a discharge passage through which, in use, molten metal will flow; and electrical induction coil located about the passage; means to supply an alternating electric current to the coil whereby the coil provides an alternating magnetic field which induces electric currents in any molten metal in the passage; and a center member located in the passage, the arrangement being such that interaction between the magnetic field provided by the coil and the currents induced in the molten metal in the passage provides a force which as it is increased causes the flow rate of the molten metal through the valve to be reduced until the force is sufficient to urge the molten metal away from the wall of the passage until the molten metal is supported on the center member and the flow of molten metal is cut off. The valve is also arranged to provide mixing of molten metal in the discharge passage with that in the container in order to prevent superheating or freezing of metal in the discharge passage.

대표청구항 ▼

An electromagnetic valve for use for discharge of molten metal from a container, comprising a main body providing a discharge passage through which, in use, molten metal will flow from a container under the action of gravity; an electrical induction coil located about the passage; means to supply an

An electromagnetic valve for use for discharge of molten metal from a container, comprising a main body providing a discharge passage through which, in use, molten metal will flow from a container under the action of gravity; an electrical induction coil located about the passage; means to supply an alternating electric current to the coil whereby the coil provides an alternating magnetic field which induces electric currents in any moltion metal in the passage; and a centre member located in the passage and shaped such that the passage has an upper circular cross-section parallel sided portion leading to an asymmetric outwardly tapering conical portion which in turn leads to a lower smaller diameter circular cross-section portion the axis of which is offset in relation to that of the upper portion, the centre member having a flat top located at the junction between the upper and conical portions of the passage and being supported by a single web extending from the main body, the arrangement being such that interaction between the magnetic field provided by the coil and the currents induced in the molten metal in the passage provide a force which as it is decreased causes the flow rate of the molten metal through the valve to be reduced until the force is sufficient to urge the molten metal away from the wall of the passage until the molten metal is supported on the flat top of the centre member and the flow of molten metal is cut off.