| Due to the high machining efficiency, milling has been widely used in the machinerymanufacturing. However, milling is the intermittent cutting process, so the vibrationphenomenon is more complex. Cutting tools vibration is inevitable by the cutting forceaffection in the cutting process. In the case with certain conditions will produce chatter,chatter can reduce machining precision, increase the fatigue and wear of cutting tools, evendamage cutting tools and the machining can not be continue in the end.Particle damping technology use the particle frictions and collisions with each other andwith the enclosure to cost the energy of vibrating structures and prevent the vibration ofstructures. According to the mechanism of particle damping technology, to design a particledamping milling cutter in this thesis. Using the frictions and collisions between particleswhich are filled in the milling cutter cavity to cost the energy and prevent vibration of millingcutter. The main content is as follows:(1)Introducing the reasons of causing vibration in the machining process and themethods of controlling vibration. The material of milling cutter was selected. The dynamicmodel of ordinary milling cutter and particle damping milling cutter was established. Theinfluence of damping ration on the amplitude of milling cutter was analyzed. The cavity ofmilling cutter was designed. The characteristics of the models and static stiffness of two kindsof milling cutter was analyzed, then its natural frequency was got respectively.(2)The property of particle materials was introduce, such as basic featuresã€static andvibration properties. The DEM was introduced and the model of DEM was established. Thenormal force, shear force and rotational torque of particle contact was analyzed theoretically. The mechanism of friction and cost energy of particle was introduced.(3)The theory model of particle collisions was established. The state of motion andcontact force of different stages in the particle collisions process. The two balls collision wassimulated by the finite element analysis, and the energy loss was analyzed in the particleprocess.(4)The effect of preventing vibration of damping particle and the milling performance ofparticle damping milling cutter was verify by experiment. The damping ratio of milling cutterwith filling different particles was tested, and the particle damping milling cutter was used tomilling plane, and the milling force and surface roughness of workpiece was got, then theeffect and discipline of preventing vibration of damping particles was analyzed. |
