共振現象を利用した変位拡大機構による非円形旋削加工(第1報)

開ループ制御による楕円形状加工の実現

抄録

A new non-circle turning machine has been developed to obtain the oval profile which is required as the cross sectional profile of automobile piston. In this machine, an original displacement enlargement mechanism that vibrates synchronizing with spindle rotation of an NC lathe is adapted. This mechanism is driven by PZT electric device, which has not enough elongation originally, exciting the representative point of the beam support on the tool base. The resonant frequency is designed the twice of fundamental rotation frequency so that the target profile is machined as oval one. The ordinary pistons are machined by copy lathe. The maximum revolution seldom exceeds 800rpm because of the limitation of dynamic characteristics depending on stylus follower. There are various NC lathes equipped additional axis and/or linear motor to solve this problem. These kinds of machine are not suitable for mass-production but these should be used for flexible manufacturing. Although the developed turning lathe machine is so simple that only the specific spindle revolution is acceptable, this machine is the most suitable for mass-production. Experimental turning machining results showed the profile deviations for various oval targets settled within ±2.0μm compared with the conventional profile tolerance of 10μm.