Tool head, machine tool and boring method of bore of cylinder block using the machine tool

摘要

The spindle drive unit of a combined machine tool drives the spindle. The tip end of the spindle is provided with a boring tool and a tool head having a rough grinding stone and a finishing grinding stone. The spindle drive unit has a first support unit and a second support unit capable of receiving the spindle therethrough and supporting it rotatably, a linear motor and a column slide mechanism for moving the first and second support unit in the axis direction of the spindle, and a spindle motor for rotating the spindle.