抄録
In order to keep efficient an electrospark machining, the discharge gap between an electrode and a work should be controlled by automatic electrode feeding apparatus. For this feeding apparatus, a continuous servomechanism generally had been used, however, the authors adopted an on-off servomechanism utilizing stepping motors, instead. Features of the stepping motor that the overshoot at stopping is very small and the response is very quick make it possible to present an on-off servomechanism without hunting. The stepping motor is of two phase type with mechanical oneway brake. For driving the stepping motor, flip-flop method, AC method and DC superposed AC method were developed. To investigate performances of the stepping motor-driven feeding apparatus, working tests were made by means of RC discharge circuit. The test results expressed by relationship between working speed and worked surface roughness indicate that the stepping motor-driven feeding servomechanism is effective by either flip-flop driving method or AC driving method.
