GB/T 40742.4-2021Geometrical product specifications (GPS)—Geometrical precision verification—Part 4: Evaluation of dimension and geometrical error，discriminant pattern of minimum zone (English PDF)

Foreword

This document is in accordance with the provisions of GB/T 1.1-2020 "Guidelines for Standardization Work Part 1: Structure and Drafting Rules of Standardization Documents" Drafting.

This document is part 4 of GB/T 40742 "Geometrical Technical Specifications for Products (GPS) Geometric Accuracy Testing and Verification".

GB/T 40742 has released the following parts.

---Part 1: Basic concepts and measurement basic symbols, terminology, measurement conditions and procedures;

---Part 2: Detection and verification of shape, direction, position, runout and profile features;

---Part 3: Testing and verification of functional gauges and fixtures when applying the largest and smallest physical requirements;

---Part 4: Size and geometric error evaluation, minimum area discrimination mode;

---Part 5: Evaluation of measurement uncertainty in geometric feature detection and verification.

Introduction

In the production process, the digital measurement and control method for the geometric accuracy of the product size, shape, direction, position, etc. is imperfect, and the geometric accuracy is counted.

Key issues such as the lack of characterization inspection methods and measurement uncertainty evaluation methods, and the passive backwardness of process quality accuracy measurement and control methods.

The digital measurement theory, method and technology of product geometric accuracy, and build a geometric accuracy inspection operation specification system and control system in line with the new generation of GPS. System strategy.

GB/T 40742 "Geometrical Technical Specifications for Products (GPS) Detection and Verification of Geometric Accuracy" is based on the new generation of GPS product geometrical specifications.

Model system, using digital online measurement technology, statistical learning and analysis theory, advanced manufacturing technology, system integration and management technology, etc., through Theoretical analysis, model mapping and simulation/experimental verification are the recommended national standards for geometric accuracy testing and verification.

The standard is based on the proposed inspection operator specification, and analyzes the measurement equipment, measurement methods, measurement principles and measurement involved in the actual measurement process.

Influencing factors such as measurement conditions, the uncertainty composition and transmission law of the elements in the extraction, filtering, and fitting operations are given, and the uncertainty is established.

Degree evaluation model. Through the online collection of product quality parameters, data processing and system evaluation in the production process, it effectively solves the problem of Data extraction, error separation, fitting evaluation, quality analysis and other operations and process accuracy control of digital measurement of quality accuracy in the production process Fan unification problem.

GB/T 40742 is mainly used to standardize key element operations and standard strategies, and establish corresponding geometric accuracy inspection operation models and inspections Operators provide technical support for the analysis and improvement of product production quality. For the convenience of readers, the standard is divided into 5 parts.

Compiled, the five parts are interrelated and independent, which together constitute the content of geometric accuracy detection and verification.

GB/T 40742 is composed of 5 parts.

---Part 1: Basic concepts and measurement basic symbols, terminology, measurement conditions and procedures. Provisions for geometric accuracy testing and verification The basic concepts, measurement basis, terminology, symbols, measurement conditions and measurement procedures of the

---Part 2: Detection and verification of shape, direction, position, runout and profile features. Prescribes the shape, direction, position, and runout And the general provisions of profile detection and verification, inspection operation set, measurement uncertainty evaluation and conformity assessment, etc.

---Part 3: Testing and verification of functional gauges and fixtures when applying the largest and smallest physical requirements. Stipulates that The general requirements for the testing and verification process with the largest and smallest physical requirements and the general requirements for the design of testing fixtures.

---Part 4: Size and geometric error evaluation, the smallest area of the discriminant model. It specifies the dimensional acceptance and the evaluation operation of geometric error do. For different target tasks (offline, online inspection), the product size conformity assessment and geometric error assessment methods are given And related default principles and the minimum area discrimination method for shape error, direction error, and position error.

---Part 5: Evaluation of measurement uncertainty in geometric feature detection and verification. Specifies the uncertainty evaluation of measurement results operate. Provides an evaluation method for the uncertainty of the product size and geometric tolerance detection and verification process, and gives the basis The application specification of the Uncertainty Management Program (PUMA) for the optimization of the inspection and verification process.

1 Scope

This document specifies the size acceptance and geometric error assessment operations. For different target tasks (offline, online inspection), the production Product size conformity evaluation, geometric error evaluation method and related default principles and minimum area of shape error, direction error, and position error Discriminant.

This document is applicable to the detection and verification of geometric features such as product size, shape, direction, position, and runout.

2 Normative references

The content of the following documents constitutes an indispensable clause of this document through normative references in the text. Among them, dated quotations Only the version corresponding to the date is applicable to this document; for undated reference documents, the latest version (including all amendments) is applicable to this document.

GB/T 1957-2006 Technical conditions for smooth limit gauges

GB/T 1958 Product Geometric Technical Specification (GPS) Geometric Tolerance Testing and Verification

GB/T 3177-2009 Product Geometric Technical Specification (GPS) Inspection of smooth workpiece size

GB/T 16671 Product Geometric Technical Specification (GPS) Geometric Tolerance Maximum Entity Requirements (MMR), Minimum Entity Requirements (LMR) and reversible requirements (RPR)

GB/T 17851 Product Geometric Technical Specification (GPS) Geometric Tolerance Datum and Datum System

GB/T 18779.1 Geometric Technical Specifications for Products (GPS) Measurement Inspection of Workpieces and Measuring Equipment Part 1: Inspection According to Specifications Qualified or unqualified rules

GB/T 24637.2 Product Geometric Technical Specification (GPS) General Concepts Part 2: Basic Principles, Specifications, Operational Sets and Uncertainties Fixed degree

JJF1001 General measurement terms and definitions

3 Terms and definitions

GB/T 1958, GB/T 16671, GB/T 17851, GB/T 24637.2 and JJF1001 and the following terms and definitions are applicable Used in this document.