双螺旋电极在深微孔电火花加工中的研究

Micro hole machining using double helix electrodes in electro discharge machining

为了提高电火花加工微小孔的效率和微孔深径比,制备双螺旋形貌结构的微细电极。在相同工艺参数条件下,通过实验与旋转削边微细电极加工微小孔的相同指标进行对比。用Fluent软件分别建立削边电极和双螺旋电极下的间隙流体的流体力学模型,并对其进行流场仿真,分别从轴向速度场、流量以及压力场进行对比分析。研究结果表明:双螺旋电极比削边电极具有更快的加工速度和更大的微孔深径比,显著提高微细电火花的加工性能。双螺旋电极的特殊形貌结构在随主轴旋转的过程中,形成2个阿基米德螺旋,增强间隙流体的Z向对流运动,从而加速新鲜工作液的流入和含电蚀碎屑工作液的排出。

To improve the efficiency of electro discharge machining（EDM） micro hole and the depth to diameter ratio of micro hole, a proposed double helix electrode（DHE） was manufactured. Fluent software was used to simulate the flow-field of interstitial fluids of the DHE and the flatted electrode. And the axial velocity field, flow rate as well as the pressure field were researched, respectively. The results show that DHE improves material removal efficiency because it has higher processing speed and larger depth to diameter ratio of microhole than flatted electrode. During the process of spindle rotation, special morphological DHE forms two Archimedes screws and strengthens the convective motion of interstitial fluid in Z axial direction. So the inflow velocity of fresh working liquid and efflux velocity of working liquid containing electrolytic corrosion fragment are all speeded up.