電気加工学会誌

抄録を表示する抄録を非表示にする

In the automobile industry, increasing the demands for better environment protection and resource conservation entails for lowering both fuel cost and exhaust emission. This is because combustor efficiency is markedly influenced by grain size, spray pattern, and the injection volume of fuel atomization. Therefore, to increase combustor efficiency it is effective to improve the size, pattern, and accuracy of nozzle holes. In mass production, conventional processing methods for nozzle holes include stamping and drilling. Noncontact processes such as electric discharge machining (EDM) has the advantages of smaller size, better pattern flexibility and better accuracy, however, they are not suitable for mass production. In this study, we introduced a new EDM method with both good accuracy and good productivity that are suitable for the finish machining of microholes having a diameter less than 0.2 mm. We found that for finish boring by EDM, the smaller the depth of cut, the lower the processing efficiency. Thus, to solve this problem, we suggested a new method that entails overlaying high frequency vibration to the electrode, and verified the effectiveness of the method by experiments. We verified the effective use of a high-frequency electrode feeding device together with the direct drive method for improving the processing efficiency. The finish EDM developed method is now in practical use in the mass production of fuel injection nozzle holes, which start as preholes made using a YAG laser.

抄録全体を表示

PDF形式でダウンロード (855K)

Electrical discharge machining (EDM) is widely used for fabricating precise metal molds. Recently, EDM finishing technology has markedly progressed, and a very fine surface roughness like that of a mirror surface can be readily obtained. Therefore, the EDMed surface is highly expected to be applied to fabricating a metal mold as it requires no hand polishing. In this case, the lifetime of the metal mold depends on the surface characteristics of the EDMed surface. In this study, the releasability of molded resin from the EDMed surface is experimentally investigated by measuring force needed to separate them using a tensile tester. Experimental results clarified that the releasability of molded resin from the EDMed surface is influenced by the average inclination of the EDMed surface profile.

抄録全体を表示

J-STAGEへの登録はこちら（無料）