Study And Design On Magnetic Powders Clamping System

Monolithic components are being widely used in the field of aerospace due to their remarkable advantages of lower weight, lower assembly and higher working reliability. However, most of them have the features like large dimension, complicated structure and inconvenient clamping, so the distortion of monolithic components is often happened during machining because of unreasonable clamping.The paper designs a clamping method of clamping workpiece using magnetic powder. The basic principle of which is that magnetic powder is magnetized under magnetic field, generating positive pressure on the workpiece wall and worktable. When the workpiece has relative movement tendency in the cutting process, it will generate friction forces on workpiece wall and worktable, thus clamping workpiece.The paper takes electromagnetic field theory and statics as the theoretical basis, then theoretically analyses the basic principles of magnetic clamping and clamping force generating mechanism, and selects 80 mesh reduced iron powder as filling magnetic powder by experimental determination of friction coefficient. Magnetic field on the magnetic powder region is simulated through finite element method (FEM), the effects of the different structural parameters of electromagnetic device and magnetic powder filling parameters to magnetic field distribution are qualitatively studied. Analyzing results show that magnetic induction value decreases with the increase of magnetic powder height, and magnetic pole length and filling width have little effect on magnetic field distribution. Moreover, self-made cell electromagnetic device is tested and results verify the accuracy and rationality of finite element modeling and calculating.Three function relations of clamping force, exciting current and height of magnetic powder are established by experimental determination and regression analysis method. Finally, the actual milling test on self-made electromagnetic device is done and the feasibility of magnetic powder clamping technology is verified.