熱変形抑制のための新しい旋盤構造設計 三次元零芯設計，セルフ強制冷却，熱同期設計

As higher precision machining is required, reducing thermal deformation of a machine tool becomes more important. Today, there are much study about the thermal deformation of machine tool; a compulsory cooling of main spindle or ball screw, a feed back control of thermal expansion, an isolation of heat source and etc. However, it is necessary to use a cooling system, a controller of temperature and a sensor of temperature or heat flux for attaining these countermeasure. After all, it costs high. Therefore, in this report, a new design of lathe structure for reducing thermal deformation has been experimentally investigated. Concepts of this design aim at a suitable cost of machine tool, low running cost, low maintenance cost and high machining accuracy. Three countermeasures which are a design of zero-center on three directions, a self compulsory cooling and a design of themal synchronism were proposed for reducing thermal deformation with low cost. It is concluded from the results that the proposed countermeasures are reasonable and effective in order to reduce thermal deformation.