There are provided a load state diagnosis device and a load state diagnosis method for a servomotor. A PLC diagnoses the load state of the servomotor which rotationally drives a rotary tool in a predetermined rotational drive direction at a constant speed. The PLC includes a detection part that detects the rotational direction of a torque acting on the servomotor, a determination part that determines whether the rotational direction of the torque detected by the detection part is consistent with the predetermined rotational drive direction, and a load index output part that outputs a load index indicating the load state of the servomotor based on a determination result of the determination part.

A power tool and a detection method for the power tool. The detection method includes collecting acceleration data, via use of an acceleration sensor of the power tool, along a tangential direction of a rotation axis of a working portion of the power tool, determining whether a proportion of the collected acceleration data that exceeds a first acceleration threshold in a preset time window exceeds a preset value, and determining that a kickback occurs in the power tool when the proportion exceeds the preset value.

A torsion washer integrally formed as a one-piece structure includes an external ring-shaped portion, a first abutting arm and a second abutting arm both separately extending from an inner edge of the external ring-shaped portion, and a connecting lever connecting the first and second abutting arms. The inner edge includes a first arc segment and an opposite second arc segment, and centers of circle of the first and second arc segments are located in a space surrounded by the inner edge. Free ends of the first and second abutting arms do not contact the inner edge. A distance between a first abutting portion of the first abutting arm and the first center of circle is less than a radius of the first arc segment. The connecting lever is spaced apart from the inner edge, allowing the first and second abutting arms to be interlinked with each other.

A torsion washer integrally formed as a one-piece structure includes an external ring-shaped portion, a first abutting arm and a second abutting arm both separately extending from an inner edge of the external ring-shaped portion, and a connecting lever connecting the first and second abutting arms. The inner edge includes a first arc segment and an opposite second arc segment, and centers of circle of the first and second arc segments are located in a space surrounded by the inner edge. Free ends of the first and second abutting arms do not contact the inner edge. A distance between a first abutting portion of the first abutting arm and the first center of circle is less than a radius of the first arc segment. The connecting lever is spaced apart from the inner edge, allowing the first and second abutting arms to be interlinked with each other.

A control method for a power tool for rotary tools comprises rotating a tool holder continuously about a working axis by a rotary drive. A rotary movement of a handle about the working axis is sensed by a motion sensor. A first angle of rotation of the handle is estimated by a first motion estimator, wherein rotary movements beneath a limit value are discounted. A second angle of rotation of the handle is estimated by a second motion estimator, wherein rotary movements beneath the limit value are taken into account. A measure for reducing the torque output of the rotary drive is activated when the first angle of rotation exceeds a first triggering threshold (A1), and when the second angle of rotation exceeds a second triggering threshold (A2) and at the same time a power output of the rotary drive exceeds a power threshold (L).

A control method for a power tool for rotary tools comprises rotating a tool holder continuously about a working axis by a rotary drive. A rotary movement of a handle about the working axis is sensed by a motion sensor. A first angle of rotation of the handle is estimated by a first motion estimator, wherein rotary movements beneath a limit value are discounted. A second angle of rotation of the handle is estimated by a second motion estimator, wherein rotary movements beneath the limit value are taken into account. A measure for reducing the torque output of the rotary drive is activated when the first angle of rotation exceeds a first triggering threshold (A1), and when the second angle of rotation exceeds a second triggering threshold (A2) and at the same time a power output of the rotary drive exceeds a power threshold (L).

A tool replacement apparatus according to the present invention includes: a turning tool magazine capable of attaching or removing a tool to/from a spindle of a machine tool; a tool replacement control unit which controls operations of turning the tool magazine and attaching or removing a tool to/from a spindle; and a setting unit which sets a rotatable range of the tool magazine. The tool replacement control unit includes: a determining unit which determines whether or not a designated rotation angle in an instruction for turning the tool magazine is within the rotatable range set by the setting unit; and a unit which stops an operation of replacing a tool when the determining unit determines that a designated rotation angle is out of a rotatable range.

An electrically powered tool (1) includes a motor (10), a battery pack (5) supplying electric power to the motor (10), a battery voltage detection circuit (17) detecting battery voltage, a current detection circuit (15) detecting current flowing through the motor (10), and a microcomputer (20) controlling driving of the motor (10). The microcomputer (20) discriminates a load state of the motor (10) according to whether or not the current flowing through the motor (10) is equal to or greater than a threshold value, and the microcomputer (20) can change the threshold value in accordance with the battery voltage. When the current flowing through the motor (10) remains below the threshold value for a predetermined period of time, the microcomputer (20) stops the supply of electric power to the motor (10).

An electrically powered tool (1) includes a motor (10), a battery pack (5) supplying electric power to the motor (10), a battery voltage detection circuit (17) detecting battery voltage, a current detection circuit (15) detecting current flowing through the motor (10), and a microcomputer (20) controlling driving of the motor (10). The microcomputer (20) discriminates a load state of the motor (10) according to whether or not the current flowing through the motor (10) is equal to or greater than a threshold value, and the microcomputer (20) can change the threshold value in accordance with the battery voltage. When the current flowing through the motor (10) remains below the threshold value for a predetermined period of time, the microcomputer (20) stops the supply of electric power to the motor (10).

To provide a tool transfer apparatus including gripping force measuring unit for tool holding unit of a tool accommodation apparatus and a machining system including the tool transfer apparatus, a handling robot can perform operation of detaching a tool from a grip positioned at a tool attachment/detachment position of a tool magazine in a machine tool and transferring the tool to a tool stocker, and operation of transferring a tool from the tool stocker and attaching the tool to a grip positioned at the tool attachment/detachment position of the tool magazine. A hand portion of the handling robot is provided with a force sensor, which can detect a load applied to the hand portion. Also, a control apparatus of the handling robot and a control apparatus of the machine tool are connected via a data cable capable of transmission and reception of information.