Control apparatus for injection molding machine

• US 7,216,005 B2
• Filed: 03/28/2006
• Issued: 05/08/2007
• Est. Priority Date: 04/01/2005
• Status: Active Grant

• Current Assignee: Nissei Plastic Industrial Co., Ltd.
• Original Assignee: Nissei Plastic Industrial Co., Ltd.
• Inventors: Iwashita, Eiki, Yamagiwa, Yoshitoshi, Shioiri, Takayoshi
• Primary Examiner(s): BARNES-BULLOCK, CRYSTAL JOY
• Application Number:
  US11/390,660
• Publication Number:
  US 20060224540A1
• Time in Patent Office: 406 Days
• Field of Search: 700/28, 700/29, 700 31- 34, 700 47- 52, 700/54, 700/71, 700103-105, 700108-110, 702/182, 702/183, 702/185, 702/194, 706 1- 6, 706 14- 16, 706/19, 706/21, 706/23, 706/25, 706/26, 706/33, 706/38, 706/41, 706902-904
• US Class Current: 700/48
• CPC Class Codes: B29C 2945/76163 Errors, malfunctioning
• CPC Class Codes: B29C 2945/76438 Start up
• CPC Class Codes: B29C 2945/76979 Using a neural network
• CPC Class Codes: B29C 45/766 the setting or resetting of moulding conditions, e.g. before starting a cycle
• CPC Class Codes: G05B 19/41875 characterised by quality surveillance of production
• CPC Class Codes: G05B 2219/32193 Ann, neural base quality management
• CPC Class Codes: G05B 2219/32194 Quality prediction
• CPC Class Codes: G05B 2219/45244 Injection molding
• CPC Class Codes: Y02P 90/02 Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]
• CPC Class Codes: Y10S 706/904 Manufacturing or machine, e.g. agricultural machinery, machine tool

Abstract

Test molding and mass-production molding are performed by an injection molding machine that includes a control apparatus in which neural networks are used. A quality prediction function determined based on the test molding is revised as necessary during mass-production molding.

Claims

1. A control apparatus for an injection molding machine, said apparatus having a neural network and operating so that information on test molding is inputted to the neural networks, a quality prediction function is determined by repeating the estimation of weight factors and thresholds on the neural networks as many times as the number of test molding cycles, and mass-production molding is begun with the quality prediction function, said control apparatus further comprising:

an upper/lower control limit determination unit for setting an upper control limit and a lower control limit for each of the monitor values that indicate the state in each part of a molding machine; and

a function revision need determining unit for setting the range between the upper control limit and lower control limit set by the upper/lower control limit determination unit as the control range, and outputting a revision command for the quality prediction function and/or generating an alarm signal from an alarm signal generating unit when the monitor values acquired during mass-production molding have deviated from the control range.

2. The control apparatus of claim 1, wherein the upper control limit is a maximum value selected from the monitor groups obtained in test molding, and the lower control limit is a minimum value selected from the monitor groups obtained in test molding.

3. The control apparatus of claim 1, the control apparatus performing control wherein an alarm signal is generated from the alarm signal generating unit when the monitor values acquired during mass-production molding have deviated from the control range, and the quality prediction function is revised and/or the operation of the molding machine is stopped either when the alarm signal has continued for a specific number of times or when the cumulative number of alarm signals has reached a specific number.

4. The control apparatus of claim 1, wherein the control apparatus comprises a calculation unit for predicting quality values by providing the monitor values to the quality prediction function, and a satisfactory product determination unit for ascertaining that the molded articles are satisfactory when the quality prediction value predicted by the calculation unit is within the required quality, and ascertaining that the molded articles are unsatisfactory when the quality prediction value does not comply with the required quality.