GB/T 40804-2021Short-term capability evaluation of machining processes on metal-cutting machine tools (English PDF)

1 Scope

This standard stipulates that the short-term capability of the machining process of the metal cutting machine tool shall be determined through the specified test piece during the acceptance of the metal cutting machine tool (i.e., indirect test)

It also gives suggestions on the test conditions, the measuring system used and the relevant requirements of the machine tool.

This standard is consistent with ISO 22514 (all parts) describing statistical methods for process management, and involves the use of these methods in machine tools and testing.

Specific application in batch processing of parts. This standard does not include functional tests that are usually performed before testing accuracy, nor does it include

Full condition test.

Appendix A provides supplementary information related to statistical evaluation. For the protocol table and analysis table of the short-term ability test, see Appendix B and Appendix C.

Appendix D is an example.

Note 1.The purpose of direct testing is to study the performance of a single machine tool, such as geometry or positioning accuracy. The short-term capability assessment is to prove that a machine tool is capable of

As a specific processing task, the short-term ability test only focuses on processed products. This means that the direct test method is more suitable for determining the machine

Based on this, the machine tool that is widely used in production is structurally improved; the short-term capability test is not suitable for detecting the error source of the machine tool.

Therefore, metal cutting machine tools are more suitable for special machine tools that mainly process specific workpieces through short-term ability assessment of the processing process, such as the production line.

Workstation, the processing time of each workpiece is less than 10min, so that at least 50 test pieces are processed per shift, less than this number will make the statistical uncertainty large

Big increase. Short-term capability assessment can also be carried out on general-purpose machine tools, such as machining centers for mass production that meet the above statistical requirements.

Note 2."Short-term capability" is a term that has been widely used in the machine tool industry and corresponds to the term "process performance" specified in ISO 22514-3.2008.

2 Normative references

The following documents are indispensable for the application of this document. For dated reference documents, only the dated version applies to this article

Pieces. For undated reference documents, the latest version (including all amendments) is applicable to this document.

ISO 4288 Geometric Technical Specifications for Products (GPS) Surface Structure. Rules and Methods for Evaluating Surface Structure by Profile Method [Geomet- ricalProductSpecifications(GPS)-Surfacetexture.Profilemethod-Rulesandproceduresforthe assessmentofsurfacetexture]

ISO 22514-3.2008 Statistical Methods in Process Management Capability and Performance Part 3.Based on Measurement Data of Discrete Parts

Processing performance research (Statisticalmethodsinprocessmanagement-Capabilityandperformance-Part 3.Ma- chineperformancestudiesformeasureddataondiscreteparts)

ISO /T R22514-4.2007 Statistical Method Capability and Performance in Process Management Part 4.Process Capability Evaluation and Performance

Measurement (Statisticalmethodsinprocessmanagement-Capabilityandperformance-Part 4.Processcapa- bilityestimatesandperformancemeasures)

3 Terms and definitions

The following terms and definitions apply to this document.