The study deals with an self-discharge gap control mechanism for electrical discharge machining (EDM) in limited space so as to manufacture curved holes applied to water channels of molds, which is difficult to create. Since holes are generally formed by drilling operations, the water channels are formed as the combination of straight holes, which leads not only to an obstruction to smooth stream of coolant but also to low efficiency and unstable performance in cooling of mold. To solve the problem, we had an idea to create a curved hole by self-movable mechanism with an automatic discharge gap controller (ADGC) for EDM. The ADGC mainly consists of a helical compression spring and helical extension ones made of shape memory alloy. From experimental results, it was found that ADGC has a potential of performing stable EDM due to controlling a discharge gap automatically without any other actuators.
[Testing machine of ADGC]
[Takeuchi lab. Home Page]
T.Ishida