关键词: 移动夹具, 定位误差, 误差映射, 焊接精度, 公差

Abstract: A new type of heavy-duty high-precision inertial friction welding machine moving fixture clamping mechanisms was designed to meet the high-precision welding quality requirements of typical parts of aircraft engines. The positioning error analysis of the moving fixture clamping mechanisms was carried out.  A theoretical model was established for the mapping relationship between the positioning component tolerance of a mobile fixture clamping mechanism and the positional error of the welded part, ignoring other influencing factors such as machine tool errors, positioning reference plane errors of welded parts, and errors caused by clamping forces and thermal deformation on the welding accuracy of welded parts, this error theoretical model was used to calculate the dimensional tolerance range of the positioning components of the mobile fixture clamping mechanism based on the required welding accuracy of a certain type of rotor, a mobile fixture clamping mechanism was designed based on the calculated tolerance range of positioning components and clamp the welded parts to complete the welding tests. The experimental results show that the maximum errors of coaxiality error, parallelism error, and axial shortening error are as 0.04 mm, 0.02 mm and 0.12 mm respectively, all error detection results meet the required welding accuracy(coaxiality error:0.06 mm; parallelism error:0.04/300 mm; axial shortening error:± 0.2 mm). It indicates that the tolerance range of each positioning component obtained through analysis is reasonable, and the error theoretical model has important theoretical guidance significance for the tolerance allocation of moving fixture positioning components in the design of heavy-duty inertial friction welding machines.

Key words: mobile fixture, positioning error, error mapping, welding precision, tolerance