Recently, the National Standard Parts Product Quality Supervision and Inspection Center and Commercial Aircraft Corporation of China signed the 'Technical Appraisal Agreement' and 'Inspection and Testing Contract' to undertake the quality inspection tasks for the standard parts of the C919 large passenger aircraft. This marks that the center's inspection business has stepped into the high-end aviation field after nuclear power and wind power.
Commercial Aircraft Corporation of China was established with the approval of the State Council. It is the main body to implement the national large passenger aircraft project and the main carrier to realize the industrialization of my country's civil aircraft. The major special project of large aircraft is a major strategic decision of the Party Central Committee and the State Council to build an innovative country, improve my country’s independent innovation capabilities and strengthen the country’s core competitiveness. It is determined by the National Medium and Long-term Science and Technology Development Plan (2006-2020). One of the major projects.
Aerospace standard parts are different from the conventional inspections of general standard parts due to the particularity of the process standard parts, including size inspection, tensile strength, shear strength, grain flow, grinding burns and other inspection items All have their own special standards. In order to ensure the smooth implementation of the high-lock bolt inspection task, the center specially established an inspection and testing team led by a senior engineer to interpret the aviation inspection standards, formulate the inspection specifications, and design and develop the design based on the shape characteristics of the high-lock bolts. Special tooling fixtures. At the same time, the center also successfully passed the COMAC inspection program review.
According to the China National Defense Science and Technology Information Network, the traditional aerospace work instructions that guide technical factory manufacturing, cutting, drilling and fastener installation are carried out by manufacturing engineers by converting 3D CAD data into drawing paper and visual aids. of. The installation of fasteners is labor-intensive and requires precise and time-consuming measurements. At present, the mechanics mark the corresponding features and dimensions on the parts according to the drawings provided by the manufacturing engineers. Northrop Grumman’s Manufacturing Technology Development Company pointed out that this method is difficult to read the drawings, quality measurements are recorded on the tape, and to meet the corresponding tolerance requirements, it is necessary to repeatedly remove and reinstall the fasteners. .
The demand for recording the in-flight status of each aircraft is also growing. The CAD design is completely different from the actual assembly situation, especially the fastener installation of aluminum alloy skin and composite material skin. The thickness of the skin varies so much, you have to choose two different lengths of fasteners. Sometimes 15-20 kinds of fasteners are needed on one skin, and the steps and gaps between adjacent skins are also To be measured. All of these tasks need to set the corresponding data in the machine, which has a high probability of error, and the data setting work in the machine is currently done manually.
The Air Force Research Laboratory funded a small business innovation research and developed a set of Fastener Installation Live Link System (EntertheFastenerInstallationLiveLinkSystem, FILLS). The system sends CAD directly to the work site by projecting work instructions. FILLS uses a commercial shelf optical projector, which is installed on the product to perform three-dimensional measurement of the product, and then directly project the work instructions on the product in the form of a variety of colors and shapes. For example, by protruding fastener holes with special radial rays, workers use optical, wireless hand-held measuring guns to measure the holes to be drilled in the skin. The thickness of the hole is stored in the machine using the color code. When the mechanic starts to install the fastener, the hole selects the appropriate length of the fastener according to the color code.