Deflection control method for engine casing milling based on adaptive support

Thin-walled casing components in aeroengines undergo significant elastic deflection under cutting forces, which can easily cause dimensional deviations and reduce machining efficiency. Effectively suppressing elastic deflection during machining is crucial for enhancing the machining quality and efficiency of casing components. Taking aeroengine casings as the research subject, this study investigates elastic deflection induced by cutting forces and proposes an adaptive deflection control method based on a support-force-adjustable fixture. First, an adaptive auxiliary support fixture considering the geometric features of the casing part was designed. Its mechanical analysis was conducted, a clamping positioning constraint model was established, and the deflection control effectiveness was verified through simulation. Second, an in-process adaptive deflection control method was established, dynamically regulating support force along the milling path. An inter-process support force compensation strategy was proposed, adjusting compensation coefficients between different processes to enhance casing milling accuracy. Finally, an adaptive auxiliary support fixture with modular adjustable support force was developed by integrating the aforementioned methods and validated during the milling of a mock-up engine casing. Compared to the condition without auxiliary support, the combined in-process and inter-process support force compensation strategy reduced elastic deflection by up to 63.04%.