GB/T 38929-2020 in English

VALID

General requirements of mirror milling process for civil aircraft skin parts

Issued on:2020-06-02
Implemented on:2020-12-01
File Format:PDF
Delivery:Via email within 1~3 business days

Price(USD)： $250.00
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Standard No:	GB/T 38929-2020
Document status:	VALID
Title in English:	General requirements of mirror milling process for civil aircraft skin parts
Title in Chinese:	民用飞机蒙皮镜像铣削工艺通用要求
Language:	English
File Format:	Electronic (PDF)
Delivery:	Via email within 1~3 business days
Issued on:	2020-06-02
Implemented on:	2020-12-01
ICS Classification:	49.040-Coatings and related processes used in aerospace industry
Chinese Classification:	V18-Cold processing technology
Professional Classification:	GB-National Standard
Related Keywords:	mirror milling process civil aircraft skin parts introduction interpretation mirror milling machine tool contour feature boundary curve process allowance control skin edge metal skin parts
Related Topics:	mirror image milling Craft pass Requirements for the use of high power mirrors General purpose GBT38929 GB/T 38929-2020 mirror milling Execution of peeler Civil aircraft parts forming

《GB/T 38929-2020民用飞机蒙皮镜像铣削工艺通用要求》由TC435（全国航空器标准化技术委员会）归口，主管部门为国家标准化管理委员会。

Introduction

Interpretation of the core content of the standard

This standard systematically specifies the requirements for the entire process of mirror milling processing of metal skin parts of civil aircraft, innovatively defines the collaborative motion relationship between the mirror milling machine tool and the top support device, and establishes a precision processing technology system for complex aviation surfaces.

Classification of key technical features

Feature type	Geometric element	Processing difficulty	Typical application
Sunk feature	Bottom surface/bottom angle surface/top surface	Boundary monotonicity control	Wing aerodynamic shape
Window feature	Side/bottom/top surface	Anti-vibration processing	Inspection port processing
Contour feature	Boundary curve	Process allowance control	Skin edge forming

Key points of process control

Key quality indicators

Online thickness measurement accuracy: ±0.03mm
Machine tool positioning accuracy: 0.015mm/500mm
Surface roughness: Ra≤1.6μm

Prevention and control of typical process defects

Case: In the processing of the wing skin of a certain type of passenger aircraft, by optimizing the sink feature programming strategy (the principle of milling thick first and then thin), the tool difference was reduced from 0.1mm to 0.03mm, and the processing efficiency was improved by 40%.

Standard implementation recommendations

Equipment selection requirements

Five-axis linkage capability: Synchronization accuracy ≤ 0.02°
Top support device: must have real-time pressure feedback function
Detection system: integrated laser thickness measurement module

Staff training system

It is recommended to establish a three-level training mechanism: process programming (≥120 hours), equipment operation (≥80 hours), quality inspection (≥60 hours), which must include practical training on precision inspection as specified in Appendix B.

More samples: YD/T 3934-2021 GB 50021-2001(2009) NB/T 47013.2-2015

Sample only — not a preview of GB/T 38929-2020