Development of a practical high-performance laser-guided deep-hole boring tool: Improvement in guiding strategy

In this study, a practical laser-guided deep-hole boring tool with a diameter of 110 mm is fabricated with a view to preventing hole deviation. Thus far, it has not been possible to control and guide the boring tool at all times during the boring process because current tool guiding approaches are not sufficiently reliable. This paper describes improvements in the following three main aspects of boring tool operation: (1) the method of impressing voltage to piezoelectric actuators used for controlling the tool position and inclination; (2) speed of actuator response; and (3) guiding strategy. After the improvements are incorporated, boring experiments are carried out using duralumin workpieces to examine the performance of the new boring tool. The experimental results show that the tool can be controlled and guided at all times. Further, the guiding accuracy of the boring tool is within a range of ±20 μm for two lines on both sides along the guiding axis, and the holes are bored along the guiding axis within a straightness range of ±25 μm, even when prebored hole having a thin part on one side of the hole wall is used.