预成形大型薄壁带筋复杂曲面构件精密铣削形线控制基础理论与实验技术研究

Preforming large-scale thin-walled and complex structure parts are typical of low rigidity, complex surface, prestressed raw materials. Due to the complicated assembling and coordinating relationship with profile of other components, requirement of high shape accuracy parts make huge difficult of manufacturing. The traditional chemical milling process for the parts are gradually replaced by new numerical control machining equipment and technique owing to serious pollution and low efficiency. This project studied the basic theory and experimental technology of profile control of precision milling preforming large-scale thin-walled and complex structure parts from the aspects of machining distortion active control and in-situ measurement and compensation. The mechanism of milling force transfer among cutting tool, workpiece, clamping system, and machine tool and internal stress evolution during the milling process. The systematic process of active distortion control based on the prediction and control of milling force, prediction of 3D stability map and chatter-free milling, optimization of material removal order and tool path generation is developed. The automated 3D in-situ measurement system based on the ultrasonic thickness measurement was studied. The numerical control milling with adaptive compensation function was developed. The integrated precision milling techniques were validated on the panel part of the carrier rocket tank.

预成形大型薄壁带筋复杂曲面构件具有弱刚性、形面复杂、预应力毛坯等特征，周边轮廓与其他零部件有复杂的装配协调关系，形状精度要求很高，制造难度极大。用于预成形大型薄壁带筋复杂曲面构件制造的传统化铣加工工艺由于污染严重，生产率低等缺点，已逐步被新型数控加工装备和技术所取代。本课题从加工变形主动控制和构件原位测量补偿两方面研究预成形大型薄壁带筋复杂曲面构件精密铣削形线控制基础理论及实验技术，揭示预成形大型薄壁带筋复杂曲面构件数控铣削过程中铣削力在刀具、工件、装夹系统、机床间的传递机理，以及内应力演变机理，获得基于铣削力预测控制、三维加工稳定性图预测和无颤振加工，材料去除顺序和刀具路径优化的变形主动控制成套工艺。研制基于超声测厚的自动化三维原位检测系统，开发具有自适应补偿功能的数控铣削技术。预成形大型薄壁带筋复杂曲面构件精密铣削成套工艺技术在运载火箭箭体贮箱壁板构件上进行应用验证。

预成形大型薄壁带筋复杂曲面构件具有弱刚性、形面复杂、预应力毛坯等特征，周边轮廓与其他零部件有复杂的装配协调关系，形状精度要求很高，制造难度极大。用于预成形大型薄壁带筋复杂曲面构件制造的传统化铣加工工艺由于污染严重，生产率低等缺点，已逐步被新型数控加工装备和技术所取代。本课题从加工变形主动控制和构件原位测量补偿两方面研究预成形大型薄壁带筋复杂曲面构件精密铣削形线控制基础理论及实验技术，首先建立了考虑刀具跳动、加工变形和加工振动等因素的瞬时动态切削力模型，然后揭示了预成形大型薄壁带筋复杂曲面构件数控铣削过程中瞬时动态铣削力在刀具、工件、装夹系统、机床间的传递机理，建立了复杂曲面构件在铣削力作用下的局部加工变形模型。揭示了毛坯残余应力在材料去除过程中的演变和传递机理，研究了复杂曲面构件加工整体变形的工艺控制方法。形成了基于铣削力预测控制、三维加工稳定性图预测和无颤振加工，材料去除顺序和刀具路径优化的变形主动控制成套工艺。研制了基于超声测厚的自动化三维原位检测系统及数控铣削补偿技术。相关技术在运载火箭箭体贮箱壁板构件上进行应用验证，实现加工变形降低40%，加工效率提升75%以上，刀具寿命提高180%以上。本项目研究成果可推广应用于航空航天大型整体结构件加工，对提升我国整体结构件加工精度，加工效率和刀具寿命具有重要意义。本项目研究期间获国家科技进步二等奖1项，授权国家发明专利3项，软件著作权2项，发表SCI/EI论文7篇，出版专著1部。