Abstract: A machine tool includes a workpiece holding unit to hold a workpiece. A tool holding unit holds a tool. At least one of the workpiece holding unit and the tool holding unit is drivingly rotatable or drivingly movable in a predetermined direction to machine the workpiece with the tool. Temperature sensors are attached to members constituting the machine tool. An estimator calculates an environmental temperature system thermal displacement amount due to a heat source outside the machine tool. A correction magnification processor calculates an environmental temperature system thermal displacement correction amount. Another estimator calculates a driving system thermal displacement amount due to a heat source in the machine tool. A thermal displacement correction amount adder obtains and outputs a total thermal displacement correction amount based on which the machine tool performs thermal displacement correction control.

Abstract: A machine tool includes a workpiece holding unit to hold a workpiece. A tool holding unit holds a tool. At least one of the workpiece holding unit and the tool holding unit is drivingly rotatable or drivingly movable in a predetermined direction to machine the workpiece with the tool. Temperature sensors are attached to members constituting the machine tool. An estimator calculates an environmental temperature system thermal displacement amount due to a heat source outside the machine tool. A correction magnification processor calculates an environmental temperature system thermal displacement correction amount. Another estimator calculates a driving system thermal displacement amount due to a heat source in the machine tool. A thermal displacement correction amount adder obtains and outputs a total thermal displacement correction amount based on which the machine tool performs thermal displacement correction control.

Abstract: A tool holder is provided that prevents chattering in a large-sized cutting tool. A tool holder 1 includes an anti-vibration device provided in a radially outer portion of a body. The anti-vibration device has a ring-shaped first anti-vibration member and a second anti-vibration member. The anti-vibration device is fixed to the body together with a cutting tool T1 by means of a bolt. Four O-rings are arranged on both sides of the first anti-vibration member, and the damper property is adjusted by pressing a pressing plate with adjuster bolts. An appropriate gap is formed between the first anti-vibration member and the body and between the first anti-vibration member and the second anti-vibration member.

Abstract: A tool holder is provided that prevents chattering in a large-sized cutting tool. A tool holder 1 includes an anti-vibration device provided in a radially outer portion of a body. The anti-vibration device has a ring-shaped first anti-vibration member and a second anti-vibration member. The anti-vibration device is fixed to the body together with a cutting tool T1 by means of a bolt. Four O-rings are arranged on both sides of the first anti-vibration member, and the damper property is adjusted by pressing a pressing plate with adjuster bolts. An appropriate gap is formed between the first anti-vibration member and the body and between the first anti-vibration member and the second anti-vibration member.