| 摘要 |
PURPOSE:To shorten a molding cycle hour, by a method wherein injection is started when a detected value of a magnetic field detecting device mounted on a tie bar for mold clamping arrives at a predetermined value. CONSTITUTION:A magnetic field is generated on a magnetic field injection molding machine 1 when a magnetic field generation coils 9, 10 are electrified after molds 2, 4 have been clamped. Then magnetic flux which is in proportion to the magnetic field generating within a cavity 7 is generated on a tie bar 6. As the result, voltage is generated in a detecting coil 12 and detected by a fluxmeter 13. This detected value is compared with a predetermined value by a presetting device 15 of starting magnetic flux of injection on a comparator 14. When the detected value arrives at the predetermined value, an injection starting signal is generated through the comparator 14 and the injection is started. This predetermined value of the starting magnetic flux of the injection is decided to be one obtained directly before arrival of magnetic flux passing through the tie bar 6 at the largest stabilized value. Accordingly, the molding cycle is shortened markedly. |
