一种基于模态耦合的薄壁零件加工可调夹具

Adjustable fixture for thin-walled parts based on modal coupling

针对薄壁零件铣削中制约加工生产效率的再生颤振问题,提出了一种用于薄壁零件加工的,基于串联模态耦合的可调工件夹具。首先,采用串联模态耦合原理设计了可调工件夹具模型,并提出了两种新的最优调谐策略(振幅调谐和负实部调谐),以提高夹具的动态刚度和铣削稳定性;其次,采用旋转弹簧和涡流模块等自适应的机构,以实现夹具模态和零件模态之间的耦合,并引入导电板进行了阻尼调节;最后,通过具有清晰模态的零件铣削试验,对该工件夹具的可行性和有效性进行了试验验证。研究结果表明:该工件夹具具有可行性和有效性,在切削深度为3 mm的情况下,薄壁零件切削表面的粗糙度由Ra 2.4μm降低至Ra 0.9μm;与常规工件夹具相比,该夹具的动态刚度和铣削稳定性得到了显著提高。

Aiming at the regenerative chatter problem which restricted the machining efficiency in the milling of thin-walled parts,an adjustable workpiece holder for machining thin-walled parts was proposed based on series mode coupling.Firstly,the adjustable workpiece fixture model was designed based on the principle of series mode coupling,and two new optimal tuning strategies(amplitude tuning and negative real part tuning)were proposed to improve the dynamic stiffness and milling stability of the fixture.Secondly,self-adaptive mechanisms such as rotating spring and eddy current module were used to realize the coupling between fixture mode and part mode,and conductive plate was introduced for damping adjustment.The feasibility and effectiveness of the workpiece fixture were verified by the part milling test with clear mode.The results indicate that the fixture is feasible and effective,the cutting surface roughness decreases from Ra 2.4μm to Ra 0.9μm when the cutting depth is 3 mm.Compared with the conventional holder,the dynamic stiffness and milling stability of the proposed holder is significantly improved.