| 摘要 |
A method and apparatus for manufacturing magnets from a magnetizable material under the influence of a magnetic field. A magnetizable material is injected into at least one mold chamber within a frame. An electromagnetic field is generated within the mold core. In the preferred embodiment of the apparatus, the electromagnetic field is established by at least one coil conducting direct current from a DC source. The magnetizable material is positioned in the circuit path of magnetic flux such that the magnetizable material is subjected to the maximum flux density and a closed loop magnetic circuit is completed by the injected magnetizable material. In the apparatus of the invention, the mold chamber is positioned in the core of the coil and thus the material is disposed with respect to the coil such that the circuit of the magnetic fields produced on energization of the coil passes directly through the magnetizable material contained in the chamber. The magnetic particles within the magnetic material are thus aligned by the magnetic field established in the core. The material is thereafter ejected from the mold and, in the preferred apparatus, ejection is aided by momentarily energizing at least one coil by an alternating current pulse of sufficient power to demagnetize the tool, but of insufficient power to demagnetize the molded magnet. |
