大长径比薄壁燃烧室壳体加工变形分析与控制技术研究

Machining Deformation and Control of a Large Length-Diameter Ratio and Thin Wall Combustor Shell

固体火箭发动机壳体的保形加工是航天装备制造的重要环节。可靠的整形工装是控制加工变形和降低尺寸偏差的前提。通过对壳体制造、装药制造及装配等过程的系统测量与分析,明确了壳体在制造过程中产生变形的基本规律。基于有限元仿真分析方法,提出了焊接变形、热处理变形的分析与控制策略。分析表明,热处理过程中的组织场和应力场变化是造成壳体变形的主要因素,通过改善工装底部支撑梁结构可以达到控制变形的目的。通过试验分析优化后工装的变形量可知,试验结果与仿真规律一致。因此,将工装底部支撑梁改为格栅式导流板后气场流动更稳定,且一次回火+整形工装对抑制壳体变形效果显著。

Shape machining of model solid rocket motor case is an essential part in aerospace equipment manufacturing.Reliable shaping tooling is the precondition to control machining deformation and reduce dimensional deviation. Through the systematic measurement and analysis of motor case manufacturing, rocket grain, assembly and other processes, the basic laws of motor case deformation in the manufacturing process are defined. Based on the finite element simulation analysis method, the analysis and control strategies of welding deformation and heat treatment deformation are put forward. The analysis shows that the change of structure field and stress field during heat treatment is the main factor causing motor case deformation. Deformation control can be achieved by improving the structure of support beam at the bottom of shaping tooling. The deformation of the optimized shaping tooling is analyzed by experiment, and the experimental results are basically in agreement with the simulation rules. The flow of gas field is more stable when the bottom support beam of the shaping tooling is changed to the grid deflector, and the effect of primary tempering-shaping tooling on restraining motor case deformation is remarkable.