| 摘要 |
PURPOSE:To exactly and stably perform injection molding by a method in which the filling coefficient of metal cavity is calculated by test injection, the profile of injection speed at which the shearing force of the melt front becomes constant is determined, and the injection speed is automatically set up. CONSTITUTION:A molten resin 20 is injected from a nozzle 3 by air shot under the condition that molds 8 are removed out, and according to detected values by a screw speed detector 13 and a pressure detector 14, a nozzle pressure loss coefficient Cn is calculated by a computer. Test injection is then made at an injection speed at which the resin 20 is packed fully into the cavity 9 of the molds 8, a packing oil pressure Pci is calculated by using the coefficient Cn, etc., and the packing coefficient beta1 of the metal cavity is further calculated. On the basis of the coefficient beta1, an injection speed profile at which the shearing force of the melt front becomes constant is determined by an injection speed profile computer 18, and an optimum injection speed is automatically set up by a speed controller 17. Exact and stable injection molding can thus be attained. |
