压气机叶片辊轧模具型腔前滑补偿方法

辊轧模腔是叶片无余量辊轧成形的关键,然而压气机叶片辊轧成形过程中存在前滑现象,造成叶片沿辊轧方向精度偏差,需要在模具型腔设计过程中补偿前滑量,以实现叶片沿积叠高度的精确成形。针对叶片辊轧前滑现象,本文提出并研究了基于辊轧前滑补偿的压气机叶片辊轧模具型腔优化设计方法。首先,在分析前滑成因及叶片截面前滑表征模型的基础上,研究了前滑补偿机理并建立了前滑补偿模型,即型腔中心角与叶片积叠高度的对应关系。在此基础上,通过提取表征叶片的工艺模型截面线族,顺次计算截面前滑值并基于前滑补偿模型对辊轧模具型腔中心角进行修正。然后,基于修正后的型腔中心角,建立叶片工艺模型截面线族到型腔截面线族的空间扇态映射法则并进行截面线映射变换,进而基于型腔截面线重构了基于前滑补偿的叶片辊轧模具型腔。最后,通过高置信度数值计算方法比较了前滑补偿模腔和直接空间几何映射模腔辊轧成形叶片的积叠高度。结果表明,优化后的模具型腔能够有效提高叶片积叠轴方向上的成形精度。

Forward slip compensation method for designing rolling mold cavity of compressor blade

Rolling cavity is the key of rolling allowance free blade,Forward slip occurs in rolling process of high-pressure compressor blade,which cause a deviation of formed blade along rolling direction,so forward slip compensation need to be considered in designing mold cavity to improve the stacking height precision of blade.Contraposing forward slip phenomenon in rolling blade,the paper proposes and researches the optimum designing method which based on forward slip compensation for mold cavity of rolling compressor blade.Firstly,based on the analysis of cause and forward slip representation of rolling blade,the forward slip compensation mechanism is studied and a compensation model,namely,relationship between roller's central angle and stack height of section is proposed.After that,a set of sections which characterized the process mold is drawn,forward slip value of every section is calculated,and relationship between roller's central angle and stack height of section is set up.Then,based on the adjusted central angle,sector mapping algorithm in space for section curves is proposed and section curves are mapped;the rolling cavity surface through mapped section curves is reconstituted.Finally,an effective numerical calculation method is used to compare the stacking height of blade formed by forward slip compensated cavity and geometric cavity.The results show that optimized design of mold cavity can accurately control the blade forming accuracy of compressor blade in stack axis direction.