| 摘要 |
<p>Back pressure control method and appts for an electric injection moulding machine can accomplish an optimum plasticisation state of a molten resin by changing smoothly and continuously a screw retreating speed at the time of metering. During the execution of the metering process, a central processing unit for numeric control, of a numeric controller mounted to an injection moulding machine rotates an injection servo-motor in a screw retreating direction at a target rotation speed equal to the product value of an override value (V) and a rotation speed designated by a numeric control program, and a central processing unit for a programmable machine controller compares periodically a resin pressure detected by a pressure sensor with a target back pressure (S6) and increases or decreases (S7, S8) the override value in accordance with the result of this comparison by a predetermined change quantity so that change does not cause a discontinuous change in the target rotation speed and eventually, in the target back pressure. @(19pp Dwg.No.1/2)@.</p> |
