Abstract: An electrode and a device for resistance spot welding are capable of preventing an occurrence of a surface spatter by using magnetism. The electrode may include a shank and a welding tip mounted to an end of the shank. A magnetic unit is installed on an outer peripheral surface of the shank to form a magnetic field and to form a Lorentz force in a direction of rotation along a circumferential direction of the shank by the magnetic field and a current flowing through the shank.

Abstract: An equalizing mechanism of a welding apparatus connects an apparatus body and a fixed bracket, and includes a fixed member on the fixed bracket, and a pressure shaft on an apparatus body close to a bottom face of the fixed member. A cutout is at a position facing the fixed member A movable member on the apparatus body accommodates the fixed member. A restrictive member located by side faces of the fixed member and the movable member restricts relative movement thereof to a direction parallel to the pressure shaft. A driven lever is supported by a front portion of the fixed member to abut on an inner front face of the movable member at one end and abut on the pressure shaft at an other end. A spring between a back portion of the fixed member and an inner back face of the movable member presses the two members to move away from each other.

Abstract: A method and system are provided for a trackless autonomous crawling all-position arc welding robot with wheels and permanent magnet caterpillar belts. A sensor detects a welding seam position and transmits the position to a tracking controller. The tracking controller sends instructions to a welding torch which may be moved in generally horizontal and vertical directions based upon the instructions. Additionally, a crawler drive controller receives the welding seam position and sends a control signal to an AC servomotor drive that positions the crawler based on the control signal.

Abstract: The invention concerns a device comprising a screw (10) with pitch (P1) driven by a motor (M), a nut (12) co-operating with the screw (10) and designed to be driven in translation in the direction of the screw axis, said nut being integral in translation with a member (14), guide means (22L, 24L) defining a linear guiding to lock the rotation of the nut in a first phase of displacement, second guide means (22H, 24H) defining a helical guiding having a reverse pitch (P2) relative to the pitch of the screw to enable the transverse pitch and hence the translational speed of the nut to be decreased in said second phase of displacement. The inventive device can be used to produce a relative displacement between the members (16 and 28) of a clamping tool.

Abstract: A spot welding system using a spot welding gun having a servomotor for driving welding tips capable of suppressing variation of pressing force due to influence of heat generated by welding current to obtain an uniform pressing force. A difference between the temperature T detected by a temperature sensor and an initial temperature T0 is multiplied by a coefficient A to obtain a pressing force compensation amount ?. A pressing force d estimated by an observer is subtracted from the compensated command pressing force p? and an obtained difference is multiplied by a constant K2 to obtain a torque command (current command) ? for driving the servomotor to press the objects by the welding tips. Since the commanded pressing force is compensated in accordance with the temperature, a constant and stable pressing force is produced without influence of the temperature variation.

Abstract: This invention provides a method of producing a series of substantially uniform spot welds between two metal parts using a servomotor driven movable electrode and an axially opposing fixed electrode. Target values for electrode displacement in producing a weld indentation and electrode squeeze force are determined for the electrodes and workpieces. During welding operations electrode displacement and electrode force measurements are continually taken and compared with the displacement and force target values. While the measured values are within a tolerance range of the target values, welding is continued using the preset parameters. When either or both of the measured electrode displacement or force value falls outside the target range the total welding current is adjusted in small increments to correct the displacement and/or force values and, thereafter, welding is continued using the new total welding current.

Abstract: An adaptable, servo-control system for force/position actuation generally includes an electric linear actuator and a controller. The controller interfaces with the electric linear actuator and with a number of I/O signals that are independent from the electric linear actuator. The controller interface to the independent I/O signals is transparent to the manner in which the I/O signals are produced. Rather the controller simply looks for the status of the I/O that is preferably received into the controller by hard-wiring or field bus I/O messaging such as from a industrial robot or programmable logic controller. The controller utilizes the I/O signals to select a number of parameters to generate a motion profile for closed loop-controlled, position actuation or force actuation of the electric linear actuator.

Abstract: A multi-axis articulatable robot with a weld gun having a pair of opposing arms, where at least one arm is movable relative to the other arm to apply pressure to a workpiece during a welding operation. At least one of the opposing arms of the weld gun can be rotatable or translatable relative to the other arm. At least one arm is moved relative to the other arm by an inverted roller screw linear actuator. The robot can include an electric controller for controlling the operation of the actuator of the weld gun as an additional axis of the robot movement. The actuator can be mounted on either of the opposing arms.

Abstract: The invention concerns a device comprising a screw (10) with pitch (P1) driven by a motor (M), a nut (12) co-operating with the screw (10) and designed to be driven in translation in the direction of the screw axis, said nut being integral in translation with a member (14), guide means (22L, 24L) defining a linear guiding to lock the rotation of the nut in a first phase of displacement, second guide means (22H, 24H) defining a helical guiding having a reverse pitch (P2) relative to the pitch of the screw to enable the transverse pitch and hence the translational speed of the nut to be decreased in said second phase of displacement. The inventive device can be used to produce a relative displacement between the members (16 and 28) of a clamping tool.

Abstract: An electric motor device for powering a tool clamp, for example a resistance welding clamp, of the type comprising a casing of an electric motor 4 the shaft of which is connected to the clamp, to control the electrodes for opening, closing and clamping them onto a metal sheet, by a system of the through-the-motor type which converts the rotary motion of the shaft into translational motion of a mechanism 5 operating the clamp, this motor being linked to a control variator and a slaving device 10 coupled to the rotor of the motor. The device 10 being arranged at the end of the motor shaft, the shaft is fitted with a gear wheel 14 which can be operated from the outside, for rotating it manually, through at least one opening 15 in the casing offset with respect to the motor shaft.

Abstract: A weld gun having a pair of opposing arms movable relative to each other to apply pressure to a workpiece during a welding operation. The opposing arms of the weld gun can be rotatable or translatable relative to each other. The opposing arms are moved relative to each other by an inverted roller screw linear actuator. The weld gun can include an electric control for controlling the operation of the actuator. The actuator can be mounted on either of the opposing arms.

Abstract: An electric motor device for powering a tool clamp, for example a resistance welding clamp, of the type comprising a casing of an electric motor 4 the shaft of which is connected to the clamp, to control the electrodes for opening, closing and clamping them onto a metal sheet, by a system of the through-the-motor type which converts the rotary motion of the shaft into translational motion of a mechanism 5 operating the clamp, this motor being linked to a control variator and a slaving device 10 coupled to the rotor of the motor.