| 摘要 |
PURPOSE: To simplify a device, and achieve a desired high temperature by disposing a device of material of favorable heat conductivity between an exciting coil and a magnetic core. CONSTITUTION: An extruder casing 1 having a through aperture 1a supports a magnetic core 2, and the magnetic core 2 is formed as a U-core. An intermediate layer 4 of heat stability is disposed between a leg part 3 of the magnetic core 2 and the casing, a jacket 5 of heat stability is installed on a yoke connecting the leg part, a layer of a tube 6 of a rectangular cross sectional surface is wound around the jacket 5, and cooling material is circulated in the tube 6. An excitation coil 7 is disposed around the intermediate layer formed of each wound body of the tube 6, and the coil 7 forms a magnetic field necessary for heating the casing 1. Cooling material is also circulated through the layer of a rectangular tube 8 around the coil 7. The layers of the tube 6 and 8 are wound in inverse directions to each other for preventing introduction of a voltage generated from the coil 7. |
