Investigation On Precision Electrochemical Machine With Two Axis And Technology For Big-twisted Blades

Aero-engine is known as the "heart" of the aircraft,and the blade is the core part of aero-engine,the quality of blade processing has a great important impact on the engine performance.With its specific advantages,electrochemical machining(ECM)has become one of the primary methods of blade manufacturing.The large distortion of blade profile and the complex flow field of electrolyte through blade body,which makes it difficult to maintain uniform and stable clearance in the process of machining.For improving the precision and surface quality of big-twisted blade,the research on precision electrolysis technology of big-twisted blade was carried out.The main research content is as follow:(1)For the large distortion of big-twisted blade profile,the change of gap in ECM of large curvature blade was analyzed.A new method for calculating the fluctuation of machining clearance is proposed,which uses the discreteness of cosine value of contour θ-angle to evaluate the fluctuation of machining clearance.By optimized the clamping angle of workpiece,which has reduced the fluctuation of machining clearance and improved the forming accuracy of large curvature blade profile.(2)For the blade basin cross section,a simulation model of flow field in Precise Electrochemical Machining(PECM)with pulsed current and vibrating cathode was established.The simulation results show that the flow velocity of electrolyte increases at large gap,accelerates the renewal of electrolyte and relaxes the flow field requirement for small gap machining.(3)Based on the analysis of the relationship between electric field,flow field,temperature field and geometric structure,a multi-field coupling simulation model of PECM with pulsed current and vibrating cathode of blade basin was established,and the temperature evolution process with time per unit cycle is obtained.The results show that the electrolytic products and heat can be better removed by PECM with pulsed current and vibrating cathode,which greatly improves the environment of the processing zone.(4)The main parameters of the machine are calculated.The layout of the machine adopts the horizontal double-head feeding mode.At the same time,the structure design of the machine body is completed,including the design of the machine structure,the design of the vibration device,the design of the working box components and the design of the feeding system.(5)For the large distortion of big-twisted blade profile,three flow modes were used to establish flow field simulation models of PECM with pulsed current and vibrating cathode.The flow field distribution of large curvature blade under three flow modes was analyzed under the condition of cathode vibration feed.(6)By analysis the essential points in the fixture design for ECM,a set of fixtures for ECM of big-twisted blade was designed based on the flow mode of "blade root feeding liquid".