Method for regulating an injection molding process

Patent metadata

Field	Value
Publication number	US-9566735-B2
Application number	US-201113580298-A
Country	US
Kind code	B2
Filing date	Jan 4, 2011
Priority date	Feb 22, 2010
Publication date	Feb 14, 2017
Grant date	Feb 14, 2017

Abstract

A method for regulating an injection molding process in which process setting variables of an injection molding machine are controlled via a regulating module, which receives data from a process-internal sensor system of the injection molding machine, data on the fabricating sequence of the injection molding component parts from an external sensor system and/or data on the quality of a fabricated injection molded component part from an online component part control, evaluates these data in a quality prognosis module and, as a function of the data evaluation, performs a change in the process setting variables of the injection molding machine, because of the change in the process setting values, the working point of the injection molding machine being changed so that the quality features of the injection molded component parts fabricated using the changed working point lie within the specified tolerances of the quality of the injection molded component parts.

First claim

What is claimed is:

1. A method for regulating an injection molding process, in which process setting variables of an injection molding machine are controlled via a regulating module, the method comprising:
receiving, at the regulating module, at least one of: (i) data from a process-internal sensor system of the injection molding machine, (ii) data on the fabricating sequence of the injection molding parts from an external sensor system, and (iii) data on a quality of a fabricated injection molded component part from an online component part control;
evaluating the received data in a quality prognosis module; and
performing, as a function of the evaluation of the data, a change in the process setting variables of the injection molding machine;
wherein responsive to the change in the process setting variables, the injection moding machine is changed from a first working point of the injection molding machine to a new working point, so that the quality features of the injection molded component parts fabricated using the new working point lie within the specified tolerances of the quality of the injection molded component parts, wherein the first working point and the new working point each include setting parameters for the process setting variables of the injection molding machine; and
wherein the injection molding machine is changed from the first working point to the new working point by:
determining the new working point, and
after the determining, changing the process setting variables in a step-wise fashion from the first working point towards the new working point so that the quality of features of an injection molded component formed at each step using the step-wise changed process setting parameters lie within the specified tolerances of the quality of the injection molded component parts.

2. The method of claim 1 , wherein process characteristic variables are ascertained within the regulating module from the data of the external sensor system and from the data of the internal-process sensor system, and a quality prognosis is carried out for at least one quality feature of an injection-molded component part from the ascertained process characteristic variables and the data of the online component part control.

3. The method of claim 2 , wherein a process stability is ascertained inside the regulating module using the ascertained process characteristic variables and, if the ascertained process stability exceeds specified boundary values, a message is output.

4. The method of claim 1 , wherein the regulating module detects sensor faults occurring during the injection molding process and corrects the detected sensor faults online.

5. The method of claim 1 , wherein a scrap gate is actuated via the quality prognosis module.

6. The method of claim 1 , wherein the regulating module includes a process setting module, the process setting module evaluating the working point of the injection molding process based on a quality prognosis from the quality prognosis module, a process drift detection, and a process stability, and if necessary based on the evaluation, the process setting module changes the working point to a new working point.

7. The method of claim 6 , wherein the quality prognosis module generates quality features and provides the generated quality features to the process setting module, which applies the generated quality features to a determination by which the new working point is selected.

8. The method of claim 6 , wherein the working point is changed to the new working point by the process setting module according to the following:
determining, based on data for the process stability from a process stability module, if the injection molding process is stable,
detecting, based on data for the process drift detection from a process drift detection module, if process drift exists,
determining, based on the quality prognosis from the quality prognosis module, if the quality features of the fabricated component parts lie outside or inside the specified tolerances,
when (i) the injection molding process is determined to be stable and the process drift is detected or (ii) the injection molding process is determined to be unstable and the quality features are determined to be outside the specified tolerances, then the new working point is deemed necessary, and
when (i) the injection molding process is determined to be unstable and the quality features are determined to be inside the specified tolerances or (ii) the injection molding process is determined to be stable and the process drift is not detected, then the new working point is deemed unnecessary.

9. The method of claim 8 , wherein the change in the process setting variables is performed to switch at least one process setting variable to at least one new process setting variable such that the new working point is constantly changing.

10. The method of claim 1 , wherein the step-wise change in the process setting variables of the injection molding machine is performed in a hierarchical sequence.

11. The method of claim 10 , wherein the hierarchical sequence changes process setting variables that are time-critical to a reaction time of the injection molding machine to a different extent compared to process setting variables that are not time-critical to the reaction time.

12. The method of claim 1 , wherein the evaluating performed in the quality prognosis module is carried out for at least one quality feature of an injection molded component part.

13. The method of claim 12 , wherein the evaluating performed in the quality prognosis module is carried out for each quality feature of the injection molded component part, wherein the injection molded component part has at least two quality features.

14. The method of claim 1 , wherein:
the quality prognosis module is included in the regulating module, and the quality prognosis module receives:
(i) process characteristic variables based on the data from the external sensor system and the data from the process-internal sensor system, and
(ii) the data from the online component part control, and

the quality prognosis module generates prognosticated quality features that the quality prognosis module provides to a process setting module included in the regulating module.

15. The method of claim 1 , wherein the changing of the process setting variables in the step-wise fashion includes forming at least one injection molded component at each step of the step-wise change.

16. The method of claim 1 , wherein the changing of the process setting variables in the step-wise fashion includes:
determining a plurality of local working points, the local working points representing changes to the process setting variables to be followed step-wise during the change from the first working point to the new working point; and
changing the process setting variables using the local working points.

17. A regulating module for regulating an injection molding process, in which process setting variables of an injection molding machine are controlled, comprising:
a receiving arrangement to receive at least one of: (i) data from a process-internal sensor system of the injection molding machine, (ii) data on the fabricating sequence of the injection molding parts from an external sensor system, and (iii) data on a quality of a fabricated injection molded component part from an online component part control; and
a quality prognosis module to evaluate the received data, performing, as a function of the evaluation of the data, a change in the process setting variables of the injectio

Assignees

• Denes Istvan
• Lehtonen-Brenner Paeivi
• Wieland Robert
• Geise Stephan
• Haag Guenter
• Liedl Philipp
• Maris-Haug Patricia
• Ackermann Jens
• Nalop Holger
• Althaus Stephan
• Bosch Gmbh Robert

Inventors

• Denes Istvan
• Lehtonen-Brenner Paeivi
• Wieland Robert
• Geise Stephan
• Haag Guenter
• Liedl Philipp
• Maris-Haug Patricia
• Ackermann Jens
• Nalop Holger
• Althaus Stephan

Classifications

• G05B2219/32188

  Teaching relation between controlling parameters and quality parameters · CPC title

• Y02P90/22

  Cross-Sectional Technologies · mapped topic

• G05B2219/32194

  Quality prediction · CPC title

• G05B2219/45244

  Injection molding · CPC title

• G05B19/41875 Primary

  characterised by quality surveillance of production · CPC title