A powder-enhanced friction stir rivet welding device includes a friction stir rivet welding spindle, a C-shaped frame and a tooling platform. The friction stir rivet welding spindle includes a rotating mechanism, a feed mechanism, a vibration-rotation mixing mechanism and a powder feeding mechanism. The friction stir rivet welding spindle is configured to realize rotation and feed movements of a rivet and feeding and mixing of a powder. The C-shaped frame is configured to fix the friction stir rivet welding spindle and the tooling platform. The tooling platform includes a force sensor, a sensor indenter, a tooling mould and a tooling platen. The tooling platform is configured to clamp a workpiece to be riveted and welded, and measure a rivet welding force of the friction stir rivet welding spindle in real time.

The invention relates to a connecting element (10) having a hollow-cylindrical shaft (12) and a drive (16), via which the shaft (12) can be driven in a direction of rotation, wherein the hollow-cylindrical shaft (12) has at least one free end, wherein the drive (16) is arranged opposite the free end, wherein a hollow space is formed by the hollow-cylindrical shaft (12). The invention is characterized in that driver structures (22) acting in the circumferential direction of the hollow-cylindrical shaft (12) are arranged in the hollow space, which, projected on the lateral surface, are arranged to extend in the setting direction on the lateral surface, rectilinearly parallel to the element mid-axis (M) or with an angular deviation of at most 20° with respect to the element mid-axis (M), and/or are arranged at the end on the drive side.

A method for joining dissimilar materials is provided. The method includes a solid-state joining process in which a rivet is plunged into a predrilled hole in a top workpiece. When the rivet contacts the bottom workpiece, ultrasonic vibration by oscillatory motion of a sonotrode, such as horizontal, vertical, or rotational motion, creates frictional heat at the interface between the rivet and the lower workpiece. With the aid of frictional heat and axial compression, metallurgical bonding is achieved at the interface between the rivet and the bottom sheet, while being below the melting temperature of the bottom workpiece. The sonotrode is retracted while the rivet remains.

Methods and devices for controlling a mechanical joining or forming process, in particular friction drilling in thin-walled materials, apply several reverse pulses acting on a process parameter to bring the course of an actual curve of the parameter more into line with the course of a predetermined nominal curve of the process parameter. The number and length of the reverse pulses and the length of the intervals between the pulses are determined as a function of at least one immediately detectable variable associated with the process parameter.

Resistance spot rivet welding systems, subsystems, and methods of use thereof are provided.

A method for producing a connection between a sandwich element and a metal element is disclosed herein. In this method, the sandwich element has an interlayer arranged between two cover elements. The method includes providing the sandwich element and the metal element; placing the sandwich element and the metal element in face-to-face contact at least partially overlapping; adding a fastener from the sandwich-element side while a base of the fastener extends within the sandwich element; and friction welding, from the metal-element side, to form a hybrid connection having a mechanical connection between the fastener and the sandwich element and a welding connection between the fastener and the metal element.

A system and method for joining multiple lightweight metal sheets to a steel sheet through friction welding that include rotating and moving a first fastener along a fastener axis towards a first workpiece, wherein the first workpiece includes a lightweight metal sheet. The system and method also include contacting the first workpiece and driving the first fastener through the first workpiece and a second workpiece. The system and method further include joining the second fastener and completing friction welding.

The present invention relates to a connecting element for non-detachably connecting at least two components by means of friction welding when the connecting element is rotated about a longitudinal axis of the connecting element. The connecting element includes a stem formed along the longitudinal axis with a stem face at a free end of the stem for penetrating at least one component, and a head connected to the stem for transmitting a torque about the longitudinal axis from a turning tool to the stem. The stem face has a stem end face which has a convex envelope with a blunt shape.

A linear actuator assembly comprises a linear actuator which has a housing and an output shaft, the output shaft defining an actuator axis and being movable along the actuator axis between an extended position and a retracted position. The assembly also comprises a buffer carriage arranged in an active configuration in which it is mounted on either the housing or the output shaft. The buffer carriage has a rotary portion which is rotationally coupled to the output shaft such that rotation of the output shaft about the actuator axis requires corresponding rotation of the rotary portion. The rotary portion is rotationally restrained when the buffer carriage is in the active configuration.

A linear actuator assembly comprises a housing, an output shaft, a nose piece and a negative pressure device. The output shaft defines an actuator assembly axis, and is movable along the actuator assembly axis between an extended position and a retracted position relative to the housing. The nose piece is slidably mounted to the output shaft and movable between an extended position and a retracted position relative to the output shaft. The nose piece and the output shaft co-operatively define a chamber for containing a quantity of fluid, the volume of the chamber being smaller when the nose piece is in the retracted position than when the nose piece is in the extended position. The negative pressure device is connectable to the chamber, and is selectively operable so as to reduce the pressure in the sealed volume, thereby urging the nose piece from the extended position towards the retracted position.