Recently, China's new carrier rocket first stage liquid oxygen tank static parts in China Aerospace Science and Technology Group Co., Ltd. Eight Academy 800 successfully closed zero, the bottom of the tank box using spinning technology overall forming, diameter of 30,.8m, for the largest overall forming box bottom in China, has passed the relevant test assessment, marking the eighth academy initially has the overall spinning box bottom engineering application capabilities. At the same time, the total length of the tank is 21m, which is one of the longest carrier rocket propellant tanks in China, and the storage tanks have been successfully closed, marking the completion of the milestone node in the development of the new launch vehicle structure.
The overall spinning technology is constantly improving
The largest bottom of the box is unveiled
As a key component of the carrier rocket tank, the bottom of the box is generally processed by the method of "block forming + welding" in China. Aiming at the needs of high reliability, lightweight and rapid manufacturing of the new launch vehicle structure, in the development of the tank, the 800 institute uses the overall spinning box bottom to replace the original melon petal welding structure box bottom. The bottom of the overall spinning box is like a thin "big bowl", which not only has a large size (diameter 3.8m, a height of about 1.2m), a small wall thickness (minimum wall thickness of 2 to 3mm), and the processing accuracy requirements are extremely high.
Taking the model demand as the traction, after more than a year of cross-professional collaborative research, 800 institutes have broken through and mastered the key core technologies such as large-diameter integral box bottom precision spinning forming, heat treatment forming collaborative control, profile precision machining, etc., developed the largest diameter of the domestic largest diameter of the overall forming box bottom, and passed various tests and assessments, realized the application on the new carrier rocket, and continuously improved the technological maturity.
Compared with the original welding structure box bottom, the overall spinning box bottom eliminates the "one ring and eight longitudinal" 9 main welds, and the single box bottom reduces the weld seam by 16.5m, which is about 60% less than the original, further improving the manufacturing accuracy and reliability of the storage box bottom. At the same time, the manufacturing process at the bottom of the box has been reduced from the original 23 to 11, the product development cycle has been shortened by more than 20%, and the labor intensity has been reduced by more than 40%.
Play the manufacturing process technology "combination punch"
The longest storage box is available
The tank, which accounts for more than 60% of the weight of the rocket structure, can be called a "bulky" part of the rocket. The first stage liquid oxygen tank of the new launch vehicle is 21 meters long, which is one of the longest propellant tanks for launch vehicles in China.
In order to further improve the quality and efficiency of product manufacturing, 800 institutes have fully optimized the tank manufacturing process program. Through the design process synergy, the merger of part types, similar parts generalization, reduce the types of parts by about 20%, tooling investment of about 30%, improve the efficiency of product development; improve the storage box barrel section wall plate processing program, the use of machine milling instead of milling to remove the aluminum plate clad aluminum layer, improve product processing accuracy, to achieve green manufacturing of the wall plate; the system optimizes the overall box bottom of the spinning forming, heat treatment, machining process scheme, to further improve product quality and development efficiency; for the storage box end frame docking hole number, more types of problems, The design can be combined with flexible drilling molds, reduce tooling input, improve production efficiency, solve the problem of multi-type end frame riveting and hole making, optimize the storage box welding tooling, and further improve the one-time pass rate of welding... Really grasp the hard work in the front line, the 800 institutes of the eight hospitals have played a "combination fist" of manufacturing technology, gathered the "energy" of tackling key problems, and opened up the "fast lane" of production.
On the basis of the successful development of the 5m-class long-barrel section in the early stage, 800 has mastered the overall forming technology of large-diameter box bottom, and the manufacturing technology of carrier rocket structure has continuously made breakthroughs, and the follow-up will continue to promote the integration, lightweight and large-scale manufacturing of carrier rocket structure around the principle of high quality, high efficiency and high efficiency, and boost the construction of a space power.
Author: Shi Bozhen Shen Honghua Zhao Tao
Editor: Zhang Yi