| 摘要 |
PURPOSE:To improve productivity, molding quality and reliability by automating stably control corresponding to mold quality, by correcting a controlled variable discriminating non-defective articles from defective articles through a monitoring range and making a physical quantity variable through an allowable range whose width is narrower than that of the monitoring range. CONSTITUTION:A monitoring range is provided to a physical quantity affecting directly to molding quality. When a measured value is between the upper limit value and lower limit value it is treated as normal and on the other hand, when the same exceeds the upper limit value or less than the lower limit value it is treated as abnormal. An allowable range(m) whose width is narrower than that of a monitoring range M is provided on the inside of the monitoring range M further. When the most advanced position of a screw is changed also by changing molding surroundings such as raising of an oil temperature while automatic operation is continued, the value exceeds the upper limit value SU as per P40 of a drawing and that the number of times of the excesses last continuously more than two times, correction is performed so as to make dwell force (controlled variable) in the next cycle small by issuing corrective instructions and making a control device (hydraulic circuit) variable. The correction is performed similarly also when the value does not arrive at the lower limit value SL and the number of times of unarrivals are continued three times.
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