Abstract: Disclosed in an automatic tool changer in which the tool changing time can be shortened by increasing overlapping operations of the turning operation and the axial advancing/retracting operation of a replacement arm. An arm driver (32) is so constituted that the driver performs overlapping operations such that at least a part of the operation for turning a replacement arm (23) by 180° and the operation for advancing/retracting the replacement arm in the axial direction in order to insert or withdraw a tool (37) are performed simultaneously and in parallelism with each other. When the replacement arm (23) is advanced/retracted in the axial direction in order to insert or withdraw a tool, the replacement arm (23) is turned by a predetermined distance in a direction reverse to the direction (so called “normal direction”) for turning the arm by 180° in parallelism with the advancing/retracting operation, and thereafter, the replacement arm (23) is turned in the normal direction.

Abstract: Disclosed in an automatic tool changer in which the tool changing time can be shortened by increasing overlapping operations of the turning operation and the axial advancing/retracting operation of a replacement arm. An arm driver (32) is so constituted that the driver performs overlapping operations such that at least a part of the operation for turning a replacement arm (23) by 180° and the operation for advancing/retracting the replacement arm in the axial direction in order to insert or withdraw a tool (37) are performed simultaneously and in parallelism with each other. When the replacement arm (23) is advanced/retracted in the axial direction in order to insert or withdraw a tool, the replacement arm (23) is turned by a predetermined distance in a direction reverse to the direction (so called “normal direction”) for turning the arm by 180° in parallelism with the advancing/retracting operation, and thereafter, the replacement arm (23) is turned in the normal direction.