Abstract
The study deals with the development of an in-pipe movable device to extend the length of a curved hole machined by means of the method proposed by the authors. To establish a curved hole machining method, authors have developed the device installed on an electrical discharge machine, which can make an electrode move along a curved trajectory with electrical discharge machining performed. This results in the fabrication of curve holes. However, the length of the curved holes is limited. Thus, the in-pipe movable device is developed to overcome the limitation. The device has a flexible body whose head is equipped with a spherical electrode and whose circumference is furnished with tiny bearings through leaf springs. It can run through a curved hole and make it longer by machining the bottom of the curved hole. From the experimental results, it is found that the device can perform a stable electrical discharge machining and extend the curved hole length.
