Design For The Downstream Pull Type Rifling Cathode And Emulation For Flow Field Of Gap

Aiming at the situation of the traditional rife cathode that the gap flow field is the spread out, the spindle of ECM machine tool suffers a force contrary to its motional direction, and the whole cathode is scraped when the working tooth is burned, a new cathode structure of the large diameter deep mixing composite rifling was designed in which the electrolyte stream reverse in the cathode body inner, downstream and the working tooth can be replaced. The key of the structure is a plug of cone by which electrolyte entered in the cathode body are reflected in all direction. After having reversed in the cathode, the electrolyte flow through the inclined hole which is connected with the guide, then get into the machining gap from the big end of working tooth to its small top, forming convergent and uniform flow distribution in machining gap. The flowing direction of the electrolyte in the machining gap is in keeping with the motional direction of the cathode and the machine loading problem is improved.The structure of the cathode is combination, so that working tooth can be replaced. It referred to as downstream pull type rifling cathode.In order to obtain the optimal design of the cone angle of the plug, the diameter of the inclined hole and the reflex hole, after having ascertained the basic structure of the downstream pull type cathode, the simulation for the flow field in the gap based on COMSOL Multiphysics was performed and a number of schemes were proposed.In condition of adjusting the cone angle of the plug, inclination of the hole, and diameter of the reflex hole, changing parameters of velocity, pressure distribution,comparing the flow velocity contour,pressure contour, streamline and the cathode structure was optimized.The results show:the pressure loss of electrolyte is lowest, to get rid of the electrolytic products is easy and the uniformity and convergence of the flow field in gap are improved when the cone angle of plug in the cathode is 100°,the inclination of inclined hole 50° and the diameter of the reflex hole 2 mm.The comparison between the force which machine tool suffered when using the downstream Rifling cathode and that when using traditional rifling cathode were carried out by finite element analysis based on UG NX. The analysis results show that the spindle of machine tool suffered maximum stress force is 0.428MPa, and the maximum displacement is 5.6355×10-5mm when using the traditional rifling cathode, however the maximum stress force 0.350MPa and the maximum displacement 4.275×10-5mm when using the pull downstream cathode. Owing to the flowing direction of the electrolyte in the gap are in keeping with the motional direction of the pull downstream cathode, whit this cathode processed, the spindle are less subjected to resistance than with traditional rifling cathode.Finally, the electrochemical machining experiments for the large diameter deep mixing rife were proceed using the pull downstream rifling cathode. The process is stable and the surface roughness Ra1.6μm。...