Control device for injection molding machine
US7311508B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 18, 2003 |
| Grant date | Dec 25, 2007 |
| Priority date | — |
| Expiry date | Oct 13, 2024 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C2045/1792
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A control device includes: a memory 29r for storing, in a process from a mold tool 10 being open until being closed, the value X(t) of a current flowing in a motor 3 at multiple points in time synchronized to the closing command signal; a mean-and-variance calculating for each of the points in time means for calculating a mean value Mx(t) and a variance value Vx(t) that correspond to current values X(t) that have been read from the memory 29r; a threshold calculating means for calculating a current threshold Xf(t) for each of the points in time using the mean value Mx(t) and the variance value Vx(t) from an arbitrary number of times up to (A−1) times, according to the following equation: Xf(t)=Mx(t)+N·{Vx(t)}1/2 where N is a constant and not less than 3; anda foreign object determining unit 29 for comparing the current threshold Xf(t) and the current value X(t) at each of the points in time to determine whether there is an abnormality according to whether the current value X(t) exceeds the current threshold Xf(t) a predetermined number m of times.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.