铅黄铜产品火焰钎焊质量控制研究——基于直升机全静压系统

Study on Quality Control of Flame Brazing on Lead Brass Products——Based on Helicopter Full Static Pressure System

铅黄铜是某直升机全静压系统选用的一种焊接式组合接头产品用材料。在生产过程中,产品容易造成螺纹变形乃至烧穿、白色钎剂残留、出现氧化膜、装配出现漏气等问题,不仅影响接头质量,也影响生产交付进度。采用火焰钎焊试验方法,对质量问题的成因进行分析,提出质量控制方法与判据。研究发现:1)在对60°锥面直通接头进行螺纹加工时,要充分考虑到镀镍(5~8μm)后要整体满足与螺母的装配需求,加强公差控制,保证精度;2)零件车间与装配车间的气密性试验要求需加以统一协调,当漏泡间隔超过15 s时,即可满足总装的整体系统级气密测试要求。质量控制措施实施后,经过半年的持续跟踪分析,质量合格率从最初的10%~20%提升至80%以上的弹性合格率,为提高直升机全静压系统和保证生产交付提供了保障。

The lead brass is a kind of welded combined joint product used material selected by a helicopter full static pressure system.During the production process,the product easily causes problems such as thread deformation and even burn-through,white solder residue,oxide film and air leakage in assembly,which not only affect the joint quality,but also affect the production delivery schedule.The flame brazing test method is used,the causes of quality problems are analyzed,and the quality control methods and criteria are put forward.It is found that:1)When machining the thread of 60 taper straight-through joint,it is necessary to fully consider that after nickel plating(5~8μm),it is necessary to meet the assembly requirements with nuts as a whole to strengthen the tolerance control and guarantee the precision;2)The air tightness test requirements of parts workshop and assembly workshop need to be unified and cooperated,and when the bubble leakage interval exceeds 15 s,the overall system-level air tightness test requirements of final assembly can be met.After the implementation of quality control measures,during half a year’s continuous attention and tracking,the qualified rate increased from the initial 10%~20%to an elastic qualified rate of more than 80%,which provided a guarantee for improving the helicopter hydrostatic system and ensuring its production delivery.