A machine tool is provided with a tool mounting part mounting and holding a tool for working a workpiece, a motor rotating the tool mounting part such that an edge of the tool is inclined with respect to the workpiece, a control device holding the tool standby such that the edge of the tool is positioned at a working standby position proximal to a surface of the workpiece and starting a working movement from the working standby position. In the machine tool, the control device includes a working standby position correcting device to correct the working standby position to a corrected working standby position according to a diameter d of the tool and a rotational angle θ of the tool mounting part such that the tool does not interfere with the workpiece when the tool is held standby at the working standby position in a rotated state by the motor.
1. A machine tool which rotatably supports a tool extending along an axis line for working an object to be worked such that an edge of the tool, at an axial end with respect to a direction of the axis line, is inclined at an inclined angle with respect to a surface of the object, which machine tool holds the tool standby such that the edge is positioned at a working standby position between a start position and a working position on a surface of the object, and starts to move the tool from the working standby position to work the object, comprising
a working standby position correcting controller device to correct the working standby position such that the tool does not interfere with the object according to a diameter of the tool and a rotational angle of the axis line of the tool and set the corrected working standby position as the working standby position when the tool is held at the working standby position in a rotated state where the edge is inclined at the inclined angle with respect to the surface of the object,
wherein the tool is a tool for working the object in contact therewith.
2. The machine tool according to claim 1 , further comprising:
a tool mounting part to hold the tool; and
a rotating device to rotate the tool mounting part, wherein the tool is configured to be rotated by a rotation of the tool mounting part by the rotating device.
3. The machine tool according to claim 1 , wherein the tool is temporarily held standby at the working standby position such that a point where a linear line perpendicular to the axis line of the tool and passing through the edge of the tool crosses the axis line of the tool is positioned at the working standby position before performing working of the object,
the tool is rotated and held such that the axis line of the tool is inclined with respect to a direction perpendicular to the surface of the object to be worked, and
the working standby position correcting device corrects the working standby position by a length of ½ of the diameter of the tool in a direction that is away from the object and perpendicular to the surface of the object to be worked.
4. The machine tool according to claim 1 , wherein the tool is temporarily held standby at the working standby position such that a point where a linear line perpendicular to the axis line of the tool and passing through the edge of the tool crosses the axis line of the tool is positioned at the working standby position before performing working of the object,
the tool is rotated and held such that the axis line of the tool is inclined with respect to a direction perpendicular to the surface of the object to be worked, and
the working standby position correcting device corrects the working standby position by a distance obtained by ½ of the diameter of the tool multiplied by a sine value of the rotational angle in a direction that is away from the object and perpendicular to the surface of the object to be worked.