According to the present invention, an axial force of a screw which is generated by screw driving is estimated. A control part applies a predetermined torque generated by a rotation axis servomotor to a screw in a rotation direction where a screw is driven, and thereafter releases the torque. The control part then estimates an axial force of the driven screw based on fluctuation of a rotation position of the rotation axis servomotor which occurs due to the release of the torque.

An electric motor-driven screwdriver includes a control circuit having a memory stored with setting data and a computing unit controlling the electric motor-driven screwdriver based on the setting data. The computing unit sets an execution order of work processes based on a pre-designated piece of order setting data, and sets, based on a next operation setting value, a next operation to be performed after completion of the final work process. The next operation setting value is selectable from among a setting value for stopping the operation of the electric motor-driven screwdriver, a setting value for repeating a series of work processes, and a setting value for shifting to a series of work processes in an execution order determined based on another piece of order setting data.

A machine tool according to the disclosure has a spindle rotatably holding a cylindrical workpiece, a turret holding a thread whirling tool having a cutter ring having a base on which a through hole is formed and a plurality of types of cutting tools disposed on the inner diameter side of the base and having different shapes, so as to rotatably holds the cutter ring, a controller controlling rotations and relative movements of the spindle and the turret, wherein the controller has the spindle hold a workpiece, disposes the workpiece in the through hole so that the workpiece penetrates the through hole, rotates at least one of the cutter ring and the workpiece, and switches movements of the thread whirling tool in an extending direction of the workpiece and a direction intersecting with the extending direction thereof based on a selected predetermined cutting tool.

An automatic screw tightening method includes measuring a datum on time-varying screw tightening torque from a motor and a datum on time-varying motor rotational speed between a screw tightening start time point for a male thread with respect to a female threaded hole and a screw tightening completion time point; extracting a plurality of features from measurement-based data on the time-varying screw tightening torque and the time-varying motor rotational speed; and determining, with use of the features, whether a tightened state of the male thread is fit or unfit. In the determination, determining a unified numerical index from the features is included, and the numerical index is compared with a predetermined threshold in the determination of whether the tightened state is fit or unfit. The numerical index is a Taguchi (T) method-based overall evaluation measure from the features.

A method and a device are provided for simplifying a flow-hole screw process, in which the difference between a process parameter and its smoothed value is employed as a criterion for changing said process parameter or another process parameter in order in particular to be able to determine the changeover point between hole forming and thread forming.

A screwing device including: a container for screws; a manipulator having an effector to pick up a screw; an isolating unit connected to the container to provide the screw from the container at an interface such that a head of the screw is accessible to the effector; and a control unit to control the manipulator in executing a control program to perform operations including: guiding the effector along a trajectory having an orientation to the screw head at the interface, wherein the orientation is defined for locations along the trajectory; and executing force-regulated, impedance-regulated, and/or admittance-regulated periodic and closed tilting movements of the effector in relation to its orientation until a condition for a torque, a force, or a time for carrying out the tilting movements is reached or exceeded, and/or a force/torque and/or a position/speed signature at the effector is reached or exceeded, indicating successful pick-up of the screw.

A tool is equipped with a torque sensor, suited for a tightening task of a fastening component of a device such as a fluid control system that requires a large number of fastening components for assembly and has a narrow space for access to the fastening components, and capable of automatically detecting a tightening torque. The tool includes a torque sensor capable of detecting a tightening torque for tightening a fastening component acting on a bit. The torque sensor initiates measurement of the tightening torque when the tightening torque detected exceeds a set threshold value, completes measurement when the tightening torque detected falls below the set threshold value and a set time elapses, and outputs torque-related data formed on the basis of measurement data from measurement initiation to measurement completion and including a measurement time. The torque-related data includes a peak value of the measurement data.

A nut runner, an attachment unit, and a sliding member are provided in a second arm that is a leading arm of the robot and has a leading end shaft movable along the direction of an elevation axis. The nut runner includes a screw fastening driver, a drive shaft rotationally driven by the screw fastening driver, and an extension bar that is so connected to rotate together with the drive shaft in the circumferential direction and to move in the axial direction. The attachment unit fixedly connects the screw fastening driver to the second arm so that a screw fastening axis parallel to the elevation axis serves as a rotation axis of the screw fastening driver. The sliding member is connected to the leading end shaft and supports the extension bar so as to move together in the axial direction and are rotatable relatively in the circumferential direction.

An object is to reduce the risk of outflow of defects and improve the work efficiency of assembly work. An assembly system 10 according to an embodiment of the present invention is used to assemble a finished product while sequentially placing and fixing multiple types of components to a workpiece. The assembly system 10 includes a collaborative robot 20 configured to collaborate with a worker 100, an identification information reading unit 27 configured to read identification information indicated on a component placed on the workpiece, and a controller 70 configured to determine whether a type of the component placed on the workpiece is correct or incorrect based on the read identification information and control the collaborative robot in accordance with a result of the correctness determination.

A screw length determination system capable of quickly determining the length of a screw is obtained. A PLC (10) is equipped with a determination part for measuring the moving speed of a driver for tightening screws in the axial direction of the driver from an initial position until a screw contacts and is screwed into a workpiece, and determining the length of the screw on the basis of the time from the start of movement from the initial position until the moving speed changes.