| 摘要 |
PURPOSE:To cause a radial yoke to be easily provided, while improving magnetic efficiency by a method in which a specified magnetic path forming projections are provided at the position surrounding the electromagnetic coils of a movable platen and a stationary platen, and a small gap is formed between said projections provided on both platens at mold clamping time. CONSTITUTION:A tie bar 1 is composed of non-magnetic material. Independently of said tie bar, magnetic path forming projections 16, 17 composed of a magnetic material extending in the direction of mold opening and closing are provided on a stationary platen 2 and/or movable platens 3, 6. A small gap g1 is contrived to be made between the projections 16, 17 provided on both platens, or between one platen and the projection at mold clamping time. The amount of magnetic flux passing through the projection may be enlarged, extending the cross sectional areas of the magnetic path forming projections 16, 17 irrespectively of the tie bar. Magnetic efficiency is improved, by suppressing the leakage of magnetic flux in said small gap to minimum, whereby strong magnetic field may be applied to a cavity with good efficiency of electric power. Because the space between the projections may be opened on a large scale, providing the magnetic path forming projections limitedly at the four corners of the cavity, etc., the removable or fitting of the mold and the piping for mold temperature control, etc. may be achieved without any hindrance. |
