Development of High-Resolution Micro-Hole Torque Sensor and Small-Size High-Speed Processing Device

Micro-hole drilling with a drill of 0.1 mm or less requires constant monitoring of machining conditions to prevent tool breakage. The micro-hole drilling machine previously developed by the authors' group is equipped with sensors to detect drilling torque and thrust force and can display both drilling forces in a real-time graph on the machine operation panel. However, the machine did not have the function to output data externally, and thus the data could not be analyzed in detail. In this study, we developed a machining force data processing device that converts signals from the sensors into numerical data at high speed and outputs the data wirelessly. And the resolution of the torque sensor was improved to enable detection of minute machining forces in drilling holes with a drill diameter of 0.03 mm. And we confirmed that the sensors had sufficient sensitivity by comparing the data detected by the sensor with the dynamometer value. Then, a calibration value was calculated using the comparison value.