Abstract: A resistance welder, which includes a clamp for supporting a detachable arm, the arm being constituted by a fixed part supporting a fixed electrode and a rotationally mobile part supporting a mobile electrode. The electrodes are intended to be crossed by an electrical current. The mobile arm of the clamp is pushed in its rotational motion by a thruster so that the extremities of the electrodes approach each other and grip the elements to be welded. The clamp further includes a shift measurement sensor, the value measured by this sensor being proportional to the distance between the extremities of the electrodes. It is thus easy to measure the distance between the electrodes and the measurement made on the piston can be used for other types of arms.

Abstract: By obtaining a spot-welded joint being a spot-welded joint formed by overlapping a plurality of pieces of steel plates (1A, 1B) and performing spot welding on the steel plates, including a high-strength steel plate whose tensile strength is 750 (MPa) to 2500 (MPa), being at least one piece of steel plate out of the plurality of pieces of steel plates, in which a carbon equivalent Ceq of the high-strength steel plate is 0.20 mass % to 0.55 mass %, and ten or more of iron-based carbides in each of which a length of a longest portion is 0.1 (?m) or more exist in a square region 103 within a heat-affected zone 4 of a cross section that passes through a center of a welding mark, and is cut along a plate thickness direction of the steel plates (1A, 1B), a cross tensile strength of the spot-welded joint to be formed is improved.

Abstract: Sandwich panels may include an intermediate thermoplastic layer disposed between two metallic cover layers. Some methods for welding a sandwich panel to a metallic component may involve heating a region of the sandwich panel with a preheating current so that the thermoplastic layer is softened and by compression of the cover layers is displaced from the welding region. A tack-welding current flowing between first and second welding electrodes may weld the cover layers together, and a welding current may be used to weld the metallic cover layers to the metallic component. In some cases, the first welding electrode may be in contact with one of the metallic cover layers, and the second welding electrode may be in contact with the metallic component. As a result, the sandwich panel may be joined to the metallic component in a short cycle time without blisters and faults arising in the sandwich component.

Abstract: A workpiece stack-up that includes at least a steel workpiece and an aluminum-based workpiece can be resistance spot welded by a spot welding method in which the welding current is controlled to perform one or more stages of weld joint development. When it is desired to terminate weld current flow and to solidify a liquid weld pool into a weld nugget (of mostly aluminum-based composition), additional cooling is applied to the outer surface of the aluminum-based workpiece around the contact area of the spot welding electrode engaging the surface of the aluminum-based workpiece surface. The additional cooling is applied and controlled so as to increase the rate of solidification of the liquid aluminum-based material and to control the direction of solidification of the weld nugget to better confine impurities, and the like, originally in the melt, at the surface of the steel workpiece.

Abstract: Devices and methods for resistance-welding a metallic component to a sandwich sheet having a thermoplastic layer disposed between two metallic cover layers may involve heating a region of the sandwich sheet to be welded such that the thermoplastic layer softens. The cover layers of the sandwich sheet may then be compressed so as to displace the thermoplastic layer from the region of the sandwich sheet to be welded. Electrical circuitry may then be employed to interconnect the metallic cover layers and the metallic component by passing a current through a pair of electrodes positioned on opposing sides of a combination including the sandwich sheet and the metallic component.

Abstract: A device includes a vacuum nozzle, a driver, a measuring unit, and a controller. The nozzle lifts and holds a photoelectric element having a first electrode and a second electrode. The driver drives the nozzle to press the photoelectric element onto a substrate having a soldering pad and a contact, such that the second electrode is electrically connected to the soldering pad via a layer of conductive glue. The measuring unit measures a resistance across the first electrode and the contact of the substrate when the photoelectric element is pressed onto the substrate. The controller controls the driver to drive the nozzle to keep pressing the photoelectric element harder and harder into the substrate until the resistance stops decreasing, that is, when the layer of conductive glue is at its thinnest.

Abstract: An arc welder including an integrated monitor is disclosed. The monitor is capable of monitoring variables during a welding process and weighting the variables accordingly, quantifying overall quality of a weld, obtaining and using data indicative of a good weld, improving production and quality control for an automated welding process, teaching proper welding techniques, identifying cost savings for a welding process, and deriving optimal welding settings to be used as pre-sets for different welding processes or applications.

Abstract: An arc welder including an integrated monitor is disclosed. The monitor is capable of monitoring variables during a welding process and weighting the variables accordingly, quantifying overall quality of a weld, obtaining and using data indicative of a good weld, improving production and quality control for an automated welding process, teaching proper welding techniques, identifying cost savings for a welding process, and deriving optimal welding settings to be used as pre-sets for different welding processes or applications.

Abstract: A weld head for spot welding two or more components together. The weld head includes first and second electrode assemblies and a linear actuator motor to drive the first electrode assembly into a desired position and apply a desired clamping force. The weld head may include a sensor configured to measure a temperature of the motor and a controller configured to monitor the temperature and adjust the current supplied to the motor to maintain the desired clamping force. The weld head may include linear encoder to measure the position of the linear actuator motor and an algorithm that correlates the position of the motor with a force constant of the motor. Based on the position of the motor and the corresponding force constant of the motor, the controller is configured to adjust the current supplied to the motor to maintain the desired clamping force.

Abstract: An arc welding system and methods. The system is capable of monitoring variables during a welding process, according to wave shape states, and weighting the variables accordingly, detecting defects of a weld, diagnosing possible causes of the defects, quantifying overall quality of a weld, obtaining and using data indicative of a good weld, improving production and quality control for an automated welding process, teaching proper welding techniques, identifying cost savings for a welding process, and deriving optimal welding settings to be used as pre-sets for different welding processes or applications.

Abstract: A method and apparatus inspect a quality of an adhesive material used for joining a pair of work surfaces during a weld-bonding process. A pair of work pieces are at least partially bonded by a layer of the adhesive material, and the dynamic displacement of one or both electrodes is measured through a duration of the resistance welding process to determine relative moisture content of the adhesive. A control action is executed when the dynamic displacement exceeds a stored threshold value. The apparatus includes a welding device having a pair of electrodes for providing a clamping force and an electrical current necessary for forming the welded joint, a sensor for measuring a dynamic displacement of at least one of the pair of electrodes and/or another portion of the welding device during formation of the welded joint. A controller has an algorithm for determining a relative moisture using the dynamic displacement.

Abstract: A method for optimizing a schedule for impulse welding including generating a weld lobe using a preexisting welding schedule, the schedule prescribing a current, a weld time, and a pressure; identifying an operating window on the weld lobe; analyzing the operating window, the analysis including determining a maximum time range of the operating window, and determining a maximum current range of the operating window; until (i) the determined maximum time range of the operating window is greater than a predetermined percentage of the prescribed weld time of the schedule and (ii) the determined maximum current range is greater than the prescribed current of the schedule, creating additional weld lobes by varying the pressure and repeating the identifying an operating window and the analyzing the operating window steps; and selecting, within the operating window satisfying conditions (i) and (ii), a second schedule including a second weld time, a second current, and a second pressure.

Abstract: A robot and a method for controlling the same are provided. The robot includes a first control unit to control the overall operation of the robot and a second control unit to supplement the function of the control unit in preparation for the malfunction of the first control unit such that the second control unit controls the robot to perform a predetermined safety-considered motion when the first control unit malfunctions.

Abstract: A method for determining a quality of at least one aluminum weld comprises detecting a force exerted on a workpiece by at least one electrode, and determining at least one factor characterizing the quality on the basis of a comparison of the detected force with at least one reference value. An aluminum welding method, a welding device set up for a corresponding operation, a welding controller and a computer program are likewise the subject matter of the disclosure.

Abstract: An electrode unit configuring a resistance welding device is provided with a first chassis section and a second chassis section. A plurality of stepped hole sections are formed in the first chassis section, and an electrode pin is slidably provided in each stepped hole section. On the head section of the electrode pin, a resin ball configuring a welding pressure adjusting mechanism is disposed. In the second chassis section, a screw hole is formed coaxially with each stepped hole section, and a setscrew configuring an extrusion output adjusting mechanism for adjusting an extrusion output of the electrode pin is screwed into each screw hole.

Abstract: An arc welder including an integrated monitor is disclosed. The monitor is capable of monitoring variables during a welding process and weighting the variables accordingly, quantifying overall quality of a weld, obtaining and using data indicative of a good weld, improving production and quality control for an automated welding process, teaching proper welding techniques, identifying cost savings for a welding process, and deriving optimal welding settings to be used as pre-sets for different welding processes or applications.

Abstract: The first embodiment of the invention is a spot welding method using a welding gun including a pair of electrodes holding and welding a welding point of a workpiece. The method including: transmitting an ultrasonic from one of the electrode pair to the workpiece with the electrode pair holding the workpiece; receiving the ultrasonic at the other electrode passed through the electrode pair and the workpiece; and detecting a holding state of the workpiece on the basis of an amplitude of the received ultrasonic. According to the embodiments of the invention, the welding gun can hold the workpiece at the proper position and with the correct angle, thereby reducing the welding flaws.

Abstract: A probeless energy delivery controller for a resistance spot welding system includes a power supply module that generates a first current and a power delivery module configured to generate a second current from the first current. The current is delivered to a first electrode and a second electrode that have at least two weld pieces interposed there-between. As the current flows through the weld pieces, the resistance and temperature of the weld pieces increase such that the weld pieces weld together. The system further includes a voltage control module that receives a current reading indicating a value of the second current, estimates a resistance of the weld pieces based on the value of the second current, and determines a phase angle for setting a voltage outputted by the power supply module based on the estimated resistance and a power profile. The power supply module generates the first current based on the phase angle.

Abstract: A system and method for providing multi-mode control of an ultrasonic welding system. In one embodiment, the control modes include the energy of the weld, the time of the welding process and the compression displacement of the parts being welded during the welding process. The method includes providing thresholds for each of the modes, and terminating the welding process after the threshold for each mode has been reached, the threshold for more than one mode has been reached or the threshold for one of the modes has been reached. The welding control can be either open-loop or closed-loop, where the open-loop process provides the mode thresholds and once one or more of those thresholds is reached the welding process is terminated. The closed-loop control provides feedback of the weld energy and/or the compression displacement so that the weld power and/or weld pressure can be increased or decreased accordingly.

Abstract: A welding method and apparatus are disclosed wherein a plurality of stacks of metal sheets are clamped together in sequence at a welding site between a pair of electrode caps across which welding current is supplied to spot weld together the sheets in each of the stacks in a series of welding operations in a production run. The electrode caps are pressed against the sheets in each of the stacks when each of the stacks is at the welding site with an applied force that includes a closing force to clamp the sheets together in a surface-to-surface interface fit plus a predetermined interjoint force that is increased progressively throughout the production run.

Abstract: An apparatus for welding a projection bolt includes a control unit which outputs an actuating signal for an advancing pressurizing means in response to at least a signal indicating completion of insertion of the projection bolt into a receiving hole and a signal indicating completion of movement of a steel plate part. Electrodes are provided for welding the projection bolt, and advancement of the electrodes from a retracted state is started in response to the actuating signal.

Abstract: In order to evaluate the welding current for the resistance seam welding of an overlap seam of container bodies, a welding with changing welding current intensity is carried out for a container body of the production series, resulting in a changing welding of the seam, ranging from the welding with a too high temperature to the welding with a too low temperature. The electric energy for this welding is determined several times during this welding and/or the temperature of the weld seam is determined several times and the welding current intensity is determined at which the welding of the individual container body is too cold and the welding current intensity at which the welding is too hot. This determination is based on the determined electric energy values and/or on the determined temperature values and based on this determination a preferred range for the welding current intensity within these limits of too hot and too cold is determined.

Abstract: A system for monitoring a weld operation is provided. The system includes an ultrasonic wave generator adapted to deliver an ultrasonic wave to a target material during the weld operation and an ultrasonic receiver adapted to receive the ultrasonic wave propagated through the target material. The system also includes a signal processor adapted to determine a quality level of a weld created during the weld operation by extracting data corresponding to a torsional mode from the ultrasonic wave and comparing the data to a profile that corresponds to an acceptable quality level.

Abstract: A method for monitoring and/or regulating the quality of spot welds of a resistance welding gun includes measuring and storing measured values during the execution of resistance spot welds at different points on a workpiece. The measured values represent a voltage, a current, a resistance, a welding time, an energy, a force on welding contacts and/or an output during the production of a resistance spot weld. The method also includes comparing the measured values with a reference measurement value. The reference measurement value represents a corresponding voltage, a current, a resistance, a welding time, an energy, a force on welding contacts and/or an output during the production of a corresponding resistance spot weld. The method also includes outputting a warning message when, during the comparison, it is established that a predetermined number of successive measured values is outside a predefined tolerance band from the reference measurement value.

Abstract: A method and an apparatus for determining the temporal curve of the voltage (ue(t)) at the electrodes (3) of a spot welding gun (1) during a spot welding process as an indicator of the welding quality, wherein the electrodes (3) are fastened to gun arms (2) that can be moved relative to each other are provided. The apparatus includes a device (9) for measuring a measuring voltage (um(t)) between the electrodes (3), that measuring device (9) being connected to measuring leads (6) extending along the gun arms (2), and further includes a compensating coil (7) for measuring a compensating voltage (uk(t)) for compensating measuring errors within measuring leads.

Abstract: A method and apparatus for evaluating the size and/or quality of a spot weld. The apparatus includes a two-dimensional array of ultrasonic transducers arranged with a delay line for positioning adjacent a surface of a weld. A layer of gel is placed between the delay line and the weld surface. The array of transducers emit ultrasonic waves that pass into the weld. The reflected waves are received by the transducers and relayed to a central processing unit that analyzes the time delay, amplitude, and amplitude attenuation to calculate the border of the weld nugget, the thickness of the welded material, the thickness of the gel layer, and other factors contributing to weld quality.

Abstract: A method and apparatus for evaluating the size and/or quality of a spot weld. The apparatus includes a two-dimensional array of ultrasonic transducers arranged with a delay line for positioning adjacent a surface of a weld. A layer of gel is placed between the delay line and the weld surface. The array of transducers emit ultrasonic waves that pass into the weld. The reflected waves are received by the transducers and relayed to a central processing unit that analyzes the time delay, amplitude, and amplitude attenuation to calculate the border of the weld nugget, the thickness of the welded material, the thickness of the gel layer, and other factors contributing to weld quality.

Abstract: A spot welding system and method where pressing force of a welding electrode applied by driving a servomotor is accurately controlled. The spot welding system has a pair of welding electrodes, a servomotor (2) for driving the welding electrodes and clamping and pressing an article (12) to be welded, and a controller (100) for controlling the welding electrodes and operation of the servomotor. A pressing force detector (3) is provided in order to measure pressing force actually applied to the article (12) to be welded. The controller (100) regulates a driving current to the servo motor (2) based on the measurement value of the pressing force detector (3), controlling the pressing force applied to the article (12).

Abstract: A welding gun assembly including a housing that defines a first chamber and a second chamber. The assembly also includes a first piston moveably disposed in the first chamber and a second piston moveably disposed in the second chamber. The assembly includes an intensifying rod that can move at least partially into the first chamber due to movement of the second piston within the second chamber. The assembly includes a controller with a pressure sensor operable to detect pressure within the first chamber. The controller is operable to increase pressure within the first chamber up to a predetermined extension pressure while the intensifying rod is disposed outside of the first chamber. The controller is further operable to increase pressure within the second chamber to thereby move the intensifying rod into the first chamber to thereby increase pressure within the first chamber above the predetermined extension pressure.

Abstract: A method for detecting abrasion of both a moving side electrode (2) and a fixing side electrode (3) of a stationary type welding gun in which the moving side electrode (2) and the fixing side electrode (3) opposed to the moving side electrode (2) are provided and a workpiece (W) held by a robot (R) is to be welded, wherein reference positions of electrode ends of both of the electrodes (2) and (3) are read by an electrode end detecting device (7) attached to the robot (R), positions of the electrode ends are then detected by the electrode end detecting device (7) in a middle of welding, and amounts of abrasion of both of the electrodes (2) and (3) are calculated from a difference between the reference positions.

Abstract: A welding head for connecting weld members by resistance welding includes an infeed cylinder having a piston rod, an electrode movable via the cylinder; and a sensor arranged between the piston rod of the infeed cylinder and a readjusting spring for the rapid readjustment of the electrode. The sensor is clamped in place between contact means in a sleeve-shaped or tubular drive shaft mounted in a housing.

Abstract: A method of and device for automatically setting and updating a reference position of a welding tip of a servo spot welding gun to automatically compensate displacement of a distal end of a welding tip by abrasion thereof. A movable welding tip is moved towards a stationary welding tip to press the stationary welding tip until an estimated disturbance load reaches a fist threshold, and then moved in reverse direction away from the stationary welding tip until the disturbance load is reduced to a second threshold. The position of the movable welding tip when the disturbance load is reduced to the second threshold is set and updated as the reference position of an axis of the movable welding tip. The first threshold is set to be greater than a frictional force exerted on the axis of the movable welding tip in the motion towards the stationary welding tip, and the second threshold is set to be equivalent to the frictional force.

Abstract: An elongation amount of electronic parts to be bonded onto a substrate by thermocompression is accurately controlled, and thereby poor connection of the electronic parts is prevented. An electronic part compression bonding apparatus according to the present invention includes a compression bonding unit (41) which bonds the electronic parts onto the substrate by thermocompression, a pressure supply unit (48), a pressure control unit (83) which controls pressure, a heating unit (43) which heats the compression bonding unit (41), a temperature control unit (85), and a thermocompression bonding control unit (80) which controls the pressure control unit (83) and the heating unit (43) based on thermocompression bonding condition data in which at least one of pressure and heating temperature is variably set during a process from start until completion of a thermocompression bonding operation of the electronic parts.

Abstract: The invention relates to an ultrasonic sensor system, especially for controlling a resistance welding process. Said system comprises at least one receiver which is used to detect the ultrasonic signals from the area to be examined. At least two piezoelectric sensors (31, 32) are used as a receiver and are arranged in such a way that their polarisation direction vectors indicate various directions, said vectors being projected in a plane perpendicular in relation to the propagation direction of an ultrasonic wave to be detected.

Abstract: A weld tip testing head is presented. An alignment member has an aperture disposed therein and is coupled to a spring element. The spring element is further coupled to a mounting. The aperture is operable to removably receive a weld tip and the alignment member is operable to determine an alignment associated with the weld tip. Computer software is encoded on storage. The computer software is operable to receive the alignment from the alignment member and analyze the alignment with respect to at least one expected alignment value. The computer software is further operable to generate an alarm based on the analysis and generate a fault based on the analysis.

Abstract: A method of resistance spot welding is disclosed. The method includes providing a first metallic workpiece having a primary surface and a second metallic workpiece having a secondary surface. The method also includes positioning the primary surface into physical contact with a first electrode and a second electrode into physical contact with the secondary surface. The second electrode includes a secondary actuator. The method also includes measuring contact force between the first electrode and the second electrode, and initiating a current through the first electrode when the contact force reaches a preselected force value. The method also includes forming a weld nugget in at least the second workpiece and a depression in the primary surface of the first workpiece, and controlling the location of the weld nugget by using two different classes of electrodes. The depression in the primary surface is substantially undetectable by a visual examination. A resistance spot welding system is also disclosed.

Abstract: A resistance type pulse welding apparatus for workpieces, including a handpiece, a pair of electrodes mounted at the tip of the handpiece adapted for delivering weld current pulses to a workpiece to be welded, an electrochemical capacitor providing a high-current, low-voltage power source, and a triggering means located between the electrochemical capacitor and the electrodes to discharge the energy stored in the electrochemical capacitor through the electrodes upon the sensing of a threshold pressure between the electrodes, indicative of the forcing of the electrodes against the workpiece.

Abstract: A resistance projection welder for welding first and second work pieces to each other. The first work piece having a body with opposing sides with at least one projection extending from one of the opposing sides and contacting the second work piece to space the body from the second work piece and define an air gap therebetween when the first and second work pieces are properly oriented. First and second electrodes electrically couple with work pieces and apply an electrical current thereto. A source of pressurized air directs a stream of pressurized air toward an interface between the first work piece and one of the second work piece and the first electrode. An air flow sensor detects the flow rate of the air stream directed toward the interface and determines if the work pieces are properly oriented based on the detected air flow rate.

Abstract: A method of flash-butt welding in which the travel speed (Vt) of the machine mobile plate and the welding voltage (U2) are changed (by preset programs) and the travel speed is controlled through negative feedback by welding current, the voltage being changed discretely for each flashing fixed interval of tm duration as a function of the increment of the actual average speed of flashing details of shortening (Va) during the previous flashing interval, Va value being maintained at the present level, lower than Vm. The invention envisages a change of the coefficient of enhancement of the negative feedback in a discrete manner for each preset flashing interval of tm duration as a function of Va increment during the previous flashing interval.

Abstract: A method of and apparatus for detecting an abnormal load on a servo gun axis, capable of quickly detecting sticking of a welding tip to an object of welding before movement of a robot, without adversely affecting the object. A load applied to a servomotor for driving a welding tip of a welding gun is detected by an observer. An abnormal load signal is output when the estimated disturbance load deviates from a range defined by a reference &bgr; (&bgr;>0). A determination as to whether or not the estimated disturbance load is larger than the reference value +&bgr; is not made during a period of time from the start of a closing motion of the welding gun until the estimated disturbance load becomes smaller than a set value &agr;. When the welding tip is stuck to a workpiece, a negative estimated disturbance load smaller than −&bgr; is derived and an abnormal load Signal is outputted.

Abstract: An improved inspection system for verifying that resistance welding electrodes have been properly dressed; that associated pairs of the electrodes are aligned with each other within predetermined tolerances; and that the pressure applied by a weld gun to the electrodes and material being welded is within predetermined standards. The system incorporates low pressure air apparatus that evaluates the back pressure resulting from the fit of collet geometry relative to the form of the electrode tip, and apparatus to verify the alignment of opposing electrodes with respect to each other and incorporating fiber-optic sensors that evaluate the alignment of collets with respect to each other. The system also provides apparatus for verifying that the proper pressure is applied to the workpieces by the electrodes during the welding operation.