US 6,527,534 B1 · Ejector controller of injection molding machine

Abstract

A disturbance estimating observer is provided, which estimates a load applied to a servomotor for driving an ejector axis. When an ejector operates, the disturbance load torque estimated by the observer is sampled for each specific period (0 to j), and the data DA (0, 0) to DA (i, j) of (i+1) ejector processes are stored in a table TA in the form of cyclic storage. From this table TA, average values DB (0) to DB (j) of estimated disturbance load torques are determined in turn and they are stored in a table TB. From these average values, upper limit values DC (0) to DC (j) and lower limit values DD (0) to DD (j) of a permissible range are stored in tables TC, TD. When the determined estimated disturbance load torque has exceeded the permissible range, an abnormal load signal is outputted.

Claims16

Dependent claims

An ejector controller of an injection molding machine which drives and controls a servomotor to drive an ejector axis, comprising:

load detecting means for detecting a load applied to said servomotor;
means for detecting the load applied to the servomotor at the time of ejector operation for each molding cycle by means of said load detecting means, and means for storing the load with respect to the ejector operation time or ejector position for the latest one or a plurality of ejector operations before the present molding cycle;
means for obtaining a reference load by computing an average of loads stored in the storing means;
means for determining a permissible upper limit value from the reference load;
and discriminating means for outputting an abnormal signal when the load at the time of the present ejector operation has exceeded said permissible upper limit value.

2 more elements

Dependencies are inferred from the claim text.

Ejector controller of injection molding machine

Life of this patent

Ejector controller of injection molding machine

Life of this patent

Abstract

Claims16