Method for controlling a production process for producing components

Patent metadata

Field	Value
Publication number	US-12429859-B2
Application number	US-202017636769-A
Country	US
Kind code	B2
Filing date	Aug 17, 2020
Priority date	Aug 19, 2019
Publication date	Sep 30, 2025
Grant date	Sep 30, 2025

Abstract

A method for controlling a production process for components, wherein the components or a production device used for producing the components have or has features which are metrologically detectable. The method comprising specifying a test plan for detecting primary feature(s) and secondary feature(s) by tests, wherein the primary feature(s) is/are measured at a first test frequency and the secondary feature(s) is/are measured at a second test frequency, wherein at least one stability criterion is defined for the primary feature(s); producing the components and carrying out the test plan for producing test results in parallel, wherein solely the primary feature(s) is/are tested at the first test frequency; evaluating the determined test results; and, if at least one test result for the primary feature(s) violates the stability criterion, continuing the carrying out of the test plan, wherein at least a secondary feature is tested.

First claim

The invention claimed is:

1. A method for controlling a production process for components produced by sintering technology in which a material in powder form is provided, pressed to form a green compact using a pressing apparatus, and subsequently sintered using a sintering furnace, wherein at least the components or a manufacturing device used for producing the components have a multiplicity of metrologically detectable features, at least one feature being defined as a main feature of the components or the manufacturing device used for producing the components and at least one further feature being defined as a secondary feature of the components or the manufacturing device used for producing the components; the method having at least the following steps:
a) establishing a test plan for detecting at least one main feature and at least one secondary feature by tests, the test plan defining that the at least one main feature is to be measured with a first test frequency and defining that the at least one secondary feature is to be measured with a second test frequency; wherein the test plan further defining at least one stability criterion for the at least one main feature and the at least one secondary feature; wherein the stability criterion is established as a defined deviation from a setpoint value for the respective feature; b) producing the components using sintering technology and in parallel carrying out the test plan in order to generate test results, only the at least one main feature being tested with the first test frequency; c) evaluating the test results which have been determined;
and, upon at least one test result for the at least one main feature violating the stability criterion,
d) continuing to carry out the test plan, the at least one secondary feature at least also being tested;

wherein, upon the stability criterion of the at least one main feature being violated this is indicative of a process instability of the production process using sintering technology, and then the at least one secondary feature is tested, wherein in parallel, a corrective intervention by correcting an operation of the pressing apparatus and/or the sintering furnace is carried out in order to restore the process stability to prevent a possible impending noncompliance with a tolerance beyond which point the component is defective;

wherein, if the test results satisfy the stability criterion over a defined period of time or over a particular number of random samples or components, then the test frequency for at least one secondary feature is reduced; wherein the second test frequency is lower than the first test frequency.

2. The method as claimed in claim 1 , wherein the first test frequency comprises testing of each component.

3. The method as claimed in claim 1 , wherein at least the at least one main feature is tested in an automated fashion during the production of the component.

4. The method as claimed in claim 1 , wherein there are at least a multiplicity of secondary features, the violation of the stability criterion of the at least one main feature entailing the testing only of a selection of the secondary features.

5. The method as claimed in claim 4 , wherein there are a multiplicity of main features, the violation of a stability criterion of one main feature entailing the testing of a first selection of the secondary features and the violation of a stability criterion of another main feature entailing the testing of a second selection of the secondary features.

6. The method as claimed in claim 1 , wherein the violation of a stability criterion comprises at least one of the following states:
the test results follow a trend;
the test results fluctuate within an interval which exceeds limit values defined by the stability criterion;
the test results of at least various main features deviate from a predefined correlation of the main features.

7. The method as claimed in claim 1 , wherein at least the first test frequency is varied,
the first test frequency being increased if at least one test result for the at least one main feature violates the stability criterion; or
the first test frequency being reduced if a particular number of successive test results at least of the at least one main feature are in accordance with the stability criterion.

8. The method as claimed in claim 1 , wherein at least main features are linked to one another by a model, a variation of other main features or secondary features being inferred with the aid of test results of at least one main feature by taking the model into account; wherein testing of at least one of these main features or secondary features is initialized as soon as the violation of a stability criterion assigned to this feature is prognosed.

9. The method as claimed in claim 8 , wherein the model is validated and varied continuously with the aid of the tests carried out and the test results.

10. The method as claimed in claim 8 , wherein at least one of the following factors is taken into account by the model for the selection of the main feature or secondary feature additionally to be tested:
cost of the additional test;
time expenditure of the additional test;
availability of the required measuring device.

11. The method as claimed in claim 1 , wherein the test plan for a component to be produced is compiled at least partially in an automated fashion during the production of the component by identifying at least one main feature and one secondary feature with the aid of test results of features.

12. The method as claimed in claim 11 , wherein in addition to the testing of the at least one main feature identified, a multiplicity of other features are periodically tested in order to validate the test plan.

13. An apparatus for data processing, comprising a processor which is configured in such a way that it carries out the method as claimed in claim 1 .

Assignees

• Gkn Sinter Metals Engineering Gmbh

Inventors

• Villgrattner Thomas
• Rier Gottfried
• Ploner Meinhard
• Messner Christina

Classifications

• G05B2219/32368

  Quality control · CPC title

• G05B2219/32199

  If number of errors grow, augment sampling rate for testing · CPC title

• G05B2219/50065

  Estimate trends from past measured values, correct before really out of tolerance · CPC title

• G05B19/41875 Primary

  characterised by quality surveillance of production · CPC title