Micro Electrochemical Machining Technology For Shaped Grooves Of Engine Fuel Nozzles

Micro electrochemical machining (micro-ECM) can machine difficult-to-cut material micro parts which can’t be machined with traditional manufacturing methods easily. There are two types (4) Shaped Groove on the engine nozzle. It is difficult to cut because of the following problem:micro-size,particular structure,rectangular structure forming. Such problems have restricted the machine of this type of engine injector. For this process problems, a two stages (rough and finish) micro ECM milling process scheme is designed. It is of great significance of the machineing shaped groove and the solving of similar process problem.First, basic theory of micro electrochemical machining is studied. Two stages (rough and finish) is studied. Then ECM milling process scheme is designed. Shaped groove machining path was planned and the effect of line milling and milling mode tool path for the machining precision of nozzle abnormity groove was analyzed. According to the processing object material electrolyte formula was developed. Meanwhile,according to the shape of tiny structures, a machine manufacturing technology is proposed with anodic dissolution method. The rod micro electrode diameter of100μm microns was successfully machined. Finally, two stage ECM milling experiments of rough and finish are carried out to machine the shaped groove of engine injectors. At the rough stage, the workpiece is machined with DC voltage, a rod-shape electrode diameter of250μm to remove the most of the material by quickly ECM dissolving and obtain the shaped groove structure with small allowance saved for next process. At the finishing stage, the workpiece is machined with pulse power, a rod-shape electrode diameter of100μm,layered micro-ECM milling is used to remove the tiny material of workpiece and achieve polygon shape of groove. Some important basic parameter is studied, including:the electrolyte concentration, machining voltage, pulse width, feed speed and so on.Shaped groove of engine fuel nozzles is sucessfully machined with ECM milling based on theoretical study and experimental analysis. And machining accuracy and surface quality of theworkpiece meet the required technical requirements.The study will construct the theoretical basis of ECM milling technology to solve difficult machining problems existed in shaped groove of engine fuel nozzles and break through the machined problem of aero engine.