Typical parts that need to be machined in aircraft manufacturing, mainly aircraft fuselage structural parts and key parts of the engine:
1. Typical parts of the fuselage structure
Typical parts of the aircraft fuselage structure are beams, ribs, ribs, frames, siding, joints, slides and other parts. It is mainly composed of flat parts, elongated parts, multi-chamber parts and ultra-thin wall frame structure. The blanks are sheets, forgings and extruded aluminum alloy profiles. The material utilization rate is only about 5%-10%, and the amount of raw materials removed is large. At present, more than 90% of domestic aircraft parts are aluminum alloy parts, a small amount is stainless steel and titanium alloy steel, and more and more structural parts are used. The application of composite materials is the future development direction.
Structural features of typical parts of fuselage structural parts
(1) The outline size of the piece is getting larger and larger. If any beam parts have a length of 13m.
(2) The angle of change of the angle of the part is large, and the thin wall is ultra-thin. The thinnest part is only about 0.76mm, so the processing rigidity is poor.
(3) The structure of the parts is more and more complicated, and many parts adopt the overall structure.
(4) The dimensional accuracy and surface quality requirements of parts are getting higher and higher. For example, defects such as burrs appearing after machining some parts are not allowed to be manually removed.
Main equipment required to process typical parts of aircraft fuselage
(1) Three-axis machining center, such as large gantry vertical machining center;
(2) Five-axis linkage machining centers, such as large gantry vertical machining centers, shall be equipped with A/B swing angle milling heads or A/C swing angle milling heads;
(3) From the perspective of development, a large gantry-type dual-spindle five-axis machining center is required, and the table size is 5m×20m for processing beam parts;
(4) Processing of aluminum alloy parts requires high-power high-speed machining center, power ≥40kW, spindle speed of 20000r/min or more, with two-axis swing angle milling head;
(5) Due to the large amount of cutting of the whole aluminum alloy parts, in order to facilitate chip evacuation, it is better to require a horizontal machining center where the table can be turned over 90°. At present, there is no such horizontal machining center in China;
(6) There are many types of aircraft fuselage structural parts, different shapes, and poor process rigidity, which requires a large number of fixtures. In order to reduce costs and shorten the production preparation cycle, various flexible fixtures are required;
(7) Sheet metal forming parts mainly involve the forming of skins such as skins, profiles and pipes, and require precise forming. In order to ensure the manufacturing precision, a large-size skin stretching machine; a skin roll forming machine; a three-axis rolling leveling machine, a profile bending machine, and a duct forming machine are required. Aircraft parts assembly also requires automatic drilling and riveting equipment;
(8) In order to reduce the weight of the aircraft, the application of composite materials is more and more, and the production of composite components requires a tape laying machine, etc. (the tape laying machine is still blank in China).