超音波振動を利用しためねじの加工

（ねじり振動の利用）

抄録

Although in many cases the internal thread machining the tap is used, especially since the small diameter of the things is vulnerable to twist load, easy to break during processing. Similarly, in drilling, breakage of the tool is likely to occur in cases of small-diameter tools, difficult-to-cut materials or etc., but the authors improved by adding ultrasonic vibration. This is the effect caused by applying vibration to the tool, for example, machining becomes intermittent, the cutting resistance of the apparent decreases, the tool and the work-piece lubrication and cooling is improved in the processing portion since repeated separation and contact. This study is aimed at preventing breakage of the tool according to the same effect in the screw tapping. As a result, by adding ultrasonic vibration to tapping, the resistance of the cutting is significantly reduced, and the chips become finer, but the tool is easily broken.