ABNORMALITY DETECTION DEVICE OF POWER TRANSMISSION MEANS OF ELECTRIC INJECTION MOLDING MACHINE

摘要

PROBLEM TO BE SOLVED: To simply detect an abnormality of a power transmission means of an electric injection molding machine.;SOLUTION: When the execution of a mold closing and mold clamping process or a mold opening process is started, a loading L to a servomotor for claming the mold is read (a1), whether an absolute value of this loading L is smaller than a prescribed value A which distinguishes an established unloaded condition is judged (a2). When an absolute value is smaller than a prescribed value A and an unloaded condition is detected, a difference of loading ΔL between a present period and a previous period is divided by a periodic time ΔT to obtain an absolute value ε of a rate of a change of loading, and an abnormality signal is output when the absolute value ε of this rate of change is larger than a prescribed value B which detects an abnormality of a power transmission means (a3-a7). Since the abnormality is defined in an unloaded condition and when an absolute value of rate of change of loading is large, the abnormality of a power transmission means can be certainly detected. Moreover, a set value A is required to be just only once measured and established at an unloaded condition, a set value B is required only to be established as a larger value than a rate of change of loading at unloaded condition of a normal time, and this set value B can be established easily.;COPYRIGHT: (C)2008,JPO&INPIT