Patent ID: 6923603

Claim:
A machine tool with a feature preventing a thermal deformation, comprising a spindle head for supporting a spindle to which a tool is fitted, a column for supporting the spindle head and a table for mounting a workpiece, and machining a workpiece through a relative movement between the tool and the workpiece, characterized in that the machine tool comprises a column having an interior space which is filled with a liquid; an inlet port, disposed at a lower portion of the column, for introducing the liquid into the interior space; an outlet port, disposed at an upper portion of the column for removing the liquid from the interior spaces; a liquid circulating means including an exterior conduit, free of a means to separately cool the liquid, extending between the outlet and inlet ports, and comprising means for circulating the liquid in the interior space through the outlet port, the exterior conduit and the inlet port to flow the liquid upwardly in the interior space; and a liquid circulation controlling means for controlling the circulation of the liquid by activating and deactivating the liquid circulating means.