Abstract: To accurately make a dressing quality determination based on resistance waveforms, a dressing quality determination method determines the quality of dressing performed for electrodes when resistance welding is performed at a plurality of welding points. This method includes accumulating a known resistance waveform immediately after dressing the electrodes, and a known resistance waveform immediately before dressing the electrodes; creating, by a statistical method, a model for setting a threshold value for dressing quality determination, based on a plurality of known resistance waveforms immediately after dressing and a plurality of known resistance waveforms immediately before dressing; acquiring an unknown resistance waveform immediately after dressing the electrodes; and determining whether dressing is normal or dressing is abnormal by comparing the unknown resistance waveform immediately after dressing with the threshold value for dressing quality determination.

Abstract: A system managing a polishing state of tips of a welding gun of each welding robot installed in a production line of a vehicle includes: a robot controller storing tip polishing data including the number of polishing of the tips and a polishing amount of the tips generated after each tip dressing of the welding gun; and a server collecting the tip polishing data from the robot controller to store the collected data according to robot identification information of the robot and learning the store data through artificial neural network to generate reference data determining the polishing state of the tips corresponding to the robot identification information. The robot controller sets artificial neural network of the robot based on the reference data and determines whether a polishing state of the tips according to the number of polishing and the polishing amount of the tips is normal.

Abstract: Disclosed is a system and method to track the consumption and use period of various consumable and/or durable welding-type products via tracking the consumption and/or use of various other consumable and/or durable welding-type products. The system and method may provide alerts when the use period of a consumable and/or durable welding-type product satisfies a threshold and therefore should be replaced.

Abstract: A resistance welding device, comprising a frame for supporting a tool configured like a clamp with two arms arranged facing one another and having respective welding electrodes, of which a first arm is integral to the clamp and the second arm is assembled with the capacity of being moved with respect to the clamp by means of a first actuator, such that respective movements along a straight trajectory can be imparted to the arms of the clamp for moving their electrodes closer to or away from one another. One of the arms has a hollow head housing the corresponding electrode in a guided manner the tip of which is suitable for receiving the support of a component to be welded on the workpiece, the head and the electrode being able to adopt at least one standby position (A) in which the electrode is inside the mentioned head; and a working position (B), in which the tip of the electrode is arranged in or exceeds the inlet of the head, accordingly placing the component to be welded outside the head.

Abstract: A radially slotted welding electrode is disclosed that may be used in conjunction with a companion second welding electrode to conduct resistance spot welding on a workpiece stack-up assembly that includes a steel workpiece and an overlapping adjacent aluminum workpiece, especially when an intermediate organic material layer is disposed between the workpiece faying surfaces of the steel and aluminum workpieces. The radially slotted welding electrode includes a weld face that has a central upstanding plateau and a convex dome portion that surrounds the central upstanding plateau and which includes a plurality of circumferentially spaced trapezoidal weld face sections that include transverse upstanding arcuate ridges. Together, the central upstanding plateau and the trapezoidal weld face sections of the convex dome portion define an annular channel that surrounds the central plateau and a plurality of radial slots that communicate with and extend outwards from the central channel.

Abstract: The present invention provides a synchronous rectification module. The synchronous rectification module includes a circuit board, a transformer, two synchronous rectification sets and a grounding set. The transformer includes a primary winding and a secondary electrically-conductive foil winding. The first and second synchronous rectification sets are symmetrically disposed on the circuit board, corresponding to the transformer and electrically connected to a secondary dotted end tap and a secondary synonyms end tap of the secondary electrically-conductive foil winding respectively.

Abstract: A hybrid component is formed by a profiled component of a first material, which is materially bonded in certain sections to a component made of a second material, and is connected by a form-fit and/or force-fit connection outside the sections with a material bond. This creates sections that relieve the strains resulting from differing thermal expansion.

Abstract: The invention relates to a spot welding cap changer (1) with a cap puller (2) and two cap magazines (3, 3A), the cap puller (2) having a gripper (20) with spring-loaded, pivotable jaws (21, 22), which in response to a turning and axial pulling-off movement detaches a spot welding cap (K) of a pincer spot welding head introduced into it from a shaft of the pincer welding head in such a way that it is clamped to prevent it twisting, and the cap magazines (3, 3A) holding spot welding caps respectively in a round cap carrier (31) such that they are circularly arranged in a directed and oriented manner and are respectively transported individually one after the other into an access position against a stop (32) by an advancing force (P).

Abstract: An apparatus for interchanging welding tips of a spot welding gun. The apparatus replaces a welding tip installed in a robot arm and includes welding tip removal componentry combined with the robot arm, welding tip mounting structure combined with one side of the welding tip removal componentry, and a welding tip supply spaced apart from the welding gun at a specific distance and configured to supply a welding tip to the welding tip mounting componentry.

Abstract: A one-side spot welding method for causing an electrode to contact a welding portion of a work-piece only from one side of the work-piece to weld the work-piece, the method includes a nugget forming process of applying welding pressure to the work-piece through the electrode, and causing the work-piece to be fully electrically conducted at a predetermined current value, and a slow-cooling process of applying welding pressure to the work-piece through the electrode from the one side, and causing the work-piece to be electrically conducted at a current value lower than the predetermined current value after the nugget forming process.

Abstract: A spot welding electrode removal apparatus that is compact and durable is provided. Specifically, the apparatus includes a J-shaped operating lever, and in a position adjacent to the end of the operating lever and facing the contact member, a pressing member is provided. The operating lever is pivotably supported at a portion of the operating lever closer to the end of the operating lever than the pressing member is by a portion of the rotating case adjacent to the side of the contact member. The electrode is placed between the contact member and the pressing member, and a pivotal operation of the operating lever toward the electrode allows the pressing member and the contact member to sandwich the electrode, and a further pivotal operation of the operating lever toward the electrode allows the electrode to rotate together with the rotating case, thereby removing the electrode from a shank end.

Abstract: There is provided a spot welding apparatus. The spot welding apparatus includes a fixed electrode and a movable electrode that clamp and press a workpiece formed of stacked plates of different rigidities, and a control pressing force applicator that causes a control pressing force applying actuator to bring a receiving unit provided at a distal end of a control pressing force applying arm into contact with the workpiece so as to apply a control pressing force to the workpiece. The control pressing force applying arm is made of a non-magnetic material.

Abstract: There is provided a pressure control method for a spot welding apparatus. Upon spot-welding a workpiece while applying a preset pressure to the workpiece by a pressure actuator through a movable electrode and a fixed electrode holding a workpiece and applying a preset sub-pressure by a sub-pressure actuator through a sub-pressure unit, the workpiece is pressed with an initial pressure by the movable electrode and the fixed electrode, and an initial sub-pressure is applied through the sub-pressure unit. After that, the setting pressure is applied to the workpiece by the pressure actuator through the movable electrode and the fixed electrode, and the setting sub-pressure is applied by the sub-pressure actuator through the sub-pressure unit.

Abstract: Disclosed are assembly line equipment maintenance devices and methods. A maintenance cart is selectively engaged to a transport conveyor and integrated into a moving assembly line. The cart can include maintenance tools to refurbish robot end effector tools or replacement tools engageable by robot wrists. The maintenance or replacement tools can include a variety of maintenance equipment including weld tip dressing tools, weld force gauges, replacement weld guns, and test coupon disks.

Abstract: A method of resistance spot welding a steel workpiece and an aluminum or aluminum alloy workpiece together includes several steps. One step involves inserting a cover between the aluminum or aluminum alloy workpiece and an adjacent welding electrode. In another step, the adjacent welding electrode is pressed against cover, and another opposed welding electrode is pressed against the steel workpiece at a weld site. In yet another step, electrical current is passed between the welding electrodes, passed through the cover, and passed through the workpieces in order to initiate and grow a molten weld pool within the aluminum or aluminum alloy workpiece.

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: A method for attaching a roof panel to a roof rail of a vehicle bodyside frame, wherein the roof rail prohibiting access to an underside of an area at which the roof panel attaches to the roof panel, can include applying a single-component adhesive to a roof rail or to a portion of a roof panel that rests on the roof rail, placing the roof panel onto the roof rail, attaching the roof panel to the roof rail using single-sided spot welds, and heating the roof panel and vehicle bodyside frame to a temperature that cures the single-component adhesive.

Abstract: A welding device for welding a thicker sheet and a thinner sheet arranged congruently together. A first welding electrode having a first heat reflector or welding mirror contacts the thicker sheet with a first contact surface. A second welding electrode having a heat reflector or second welding mirror contacts the thinner sheet with a second contact surface. The first and second contact surfaces 8, 10 are at least partially congruent, and the first contact surface is larger than the second contact surface by at least a factor of two.

Abstract: A grinding system includes a period determiner that determines, on the basis of a torque of a grinder of a dresser that grinds a welding tip, whether the current period is a grinding period in which the grinder is grinding the welding tip or a non-grinding period in which the grinder is not grinding the welding tip; and an anomaly detector that detects anomalies that are associated beforehand with each of the grinding period and the non-grinding period.

Abstract: A grinding system includes a welding gun movable relative to a workpiece. A pair of clamp devices move relatively toward each other to clamp a workpiece. A welding tip is disposed on one of the pair of clamp devices. A detector detects a relative movement amount of the welding tip with respect to the other clamp device. A dresser grinds the welding tip. While the dresser is grinding the welding tip, a determinator determines whether to make the dresser end grinding the welding tip based on the movement amount detected by the detector. When the determinator determines to make the dresser end grinding the welding tip, an instructor instructs the dresser to end grinding the welding tip.

Abstract: Weld faces of electrodes for resistance spot welding are formed with a suitable area of protrusions and/or intrusions. The size, shape, and elevation or depths of the protrusions or intrusions are determined for the formation of suitable spot welds in and between metal workpieces such as aluminum or steel panels for vehicle bodies. The protrusions or intrusions are also conceived and used to form an image on at least a visible surface of the welded article to produce an attractive appearance on the surface of the welded sheet.

Abstract: A spot welding system including a welding gun with an openable/closable electrode pair; and a dressing determination device determining a quality of a shaping process applied to an electrode of the electrode pair. The dressing determination device includes a visual sensor obtaining an image of the electrode, identifying a base and a tip of the electrode on the image and measuring a distance between the base and the tip on the image, by image processing; a visual sensor control section allowing the visual sensor to measure the distance immediately before and after the shaping process is performed; a cut amount calculation section calculating a difference between the distances measured by the visual sensor immediately before and after the shaping process is performed, as a cut amount of the electrode; and a cut amount judgment section judging whether the calculated cut amount is within a predetermined acceptable range.

Abstract: An electric spot welding gun (10) includes: a servo motor (40); a push rod (50) that advances and retracts in response to rotation of a rotor (43) of the servo motor; a drive-side electrode tip (71) that is mounted to a drive-side arm (70) fixed to a leading end of the push rod; and an encoder (60) that detects the rotation angle of the rotor of the servo motor, the position of the electrode tip being offset relative to the push rod, in which the rotor and the encoder are disposed in parallel to each other in an offset plane on which the electrode tip is offset relative to the push rod, at an attitude in which a trailing end (44) of the rotor on a side opposite to a push rod side thereof and an input end (64) of the encoder are facing in the same direction.

Abstract: In a welded joint manufactured by a method of resistance spot welding thin steel sheets, when the diameter of a nugget formed from the thin steel sheets is denoted by d, on a horizontal plane passing through a nugget surrounded by a corona bond, distribution of an amount of P in a region in the nugget surrounded by a closed curve at a distance d/100 from an end portion of a weld zone toward the inside of the nugget and a closed curve at a distance d/5 from the end portion of the weld zone toward the inside of the nugget is analyzed by area analysis, and the proportion of the region in terms of area in which the concentration m (mass %) of P is more than twice the concentration M (mass %) of P of a base metal composition is 5% or less.

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: There is illustrated and described a method for joining a composite sheet metal member to an additional component, the composite sheet metal member having at least two outer covering metal sheets and at least one non-metal layer which is arranged between the covering metal sheets and the additional component having at least one outer metal layer, wherein the composite sheet metal member and the additional component are moved so as to overlap each other between two electrodes of a resistance welding unit. In order to be able to join composite sheet metal members in an operationally reliable manner by means of resistance welding, there is provision for an electrically conductive dummy element to be moved into abutment with an outer covering metal sheet and for at least one current path between the two electrodes to be closed by means of an electrically conductive dummy element.

Abstract: The invention relates to a spot welding cap changer (1) with a cap puller (2) and two cap magazines (3, 3A), the cap puller (2) having a gripper (20) with spring-loaded, pivotable jaws (21, 22), which in response to a turning and axial pulling-off movement detaches a spot welding cap (K) of a pincer spot welding head introduced into it from a shaft of the pincer welding head in such a way that it is clamped to prevent it twisting, and the cap magazines (3, 3A) holding spot welding caps respectively in a round cap carrier (31) such that they are circularly arranged in a directed and oriented manner and are respectively transported individually one after the other into an access position against a stop (32) by an advancing force (P).

Abstract: The present invention provides a “TRIP effect” cold-rolled and annealed steel sheet which has improved formability and weldability, strength between 780 and 900 MPa and elongation at fracture greater than 19%, the composition of which includes the following elements in percentages expressed by weight: 0.17%?C?0.25%, 1.5%?Mn?2%, 0.50%?Si?1%, 0.50%?Al?1.2%, whereby Si+Al?1.30%, the remainder of the composition including iron and the inevitable impurities resulting from processing. The microstructure of the sheet includes 65 to 85% ferrite and 15 to 35% islands of martensite and residual austenite. The average size of these islands of martensite and residual austenite is less than 1.3 micrometers and their shape factor is less than 3.

Abstract: A method for attaching a roof panel to a roof rail of a vehicle bodyside frame, wherein the roof rail prohibiting access to an underside of an area at which the roof panel attaches to the roof panel, can include applying a single-component adhesive to a roof rail or to a portion of a roof panel that rests on the roof rail, placing the roof panel onto the roof rail, attaching the roof panel to the roof rail using single-sided spot welds, and heating the roof panel and vehicle bodyside frame to a temperature that cures the single-component adhesive.

Abstract: Provided are a bolt for projection welding and a method of welding the same in which a portion of large fusion depth is formed in a small region and in which junction to a steel sheet part is secured in other regions, thereby realizing high weld strength and stable junction state. A bolt includes a shaft part, an enlarged diameter part, and a fusion bonding projection, the fusion bonding projection including an initial fusion part having at an end surface thereof a tapered portion and a main fusion part continuous with the initial fusion part.

Abstract: The invention relates to a spot welding cap changer (1) with a cap puller (2) and two cap magazines (3, 3A), the cap puller (2) having a gripper (20) with spring-loaded, pivotable jaws (21, 22), which in response to a turning and axial pulling-off movement detaches a spot welding cap (K) of a pincer spot welding head introduced into it from a shaft of the pincer welding head in such a way that it is clamped to prevent it twisting, and the cap magazines (3, 3A) holding spot welding caps respectively in a round cap carrier (31) such that they are circularly arranged in a directed and oriented manner and are respectively transported individually one after the other into an access position against a stop (32) by an advancing force (P).

Abstract: In an encoder dampening mechanism for an electric spot welding gun equipped with a motor that is accommodated inside of a motor housing and causes a hollow rotor to rotate, and an encoder main body that detects a rotation angle of the hollow rotor, the encoder dampening mechanism includes: a thin plate that is formed with a top surface that is larger in a surface area than a base surface of the encoder main body, and on which the base surface of the encoder main body is installed within the top surface; and a thin plate mounting portion that connects the thin plate to the motor housing via the thin plate support part and the thin plate pressure part, which dampen vibration.

Abstract: The invention belongs to the technical field of welding, and in particular relates to a spot welding clamp which avoids rosin joint, false welding and fire blasting and is used in spot welding process with high efficiency. The spot welding clamp comprises a clamp body, an electric core holding area and a fuse holding area, wherein the electric core holding area and the fuse holding area are arranged on the clamp body. A clearance is arranged between the electric core holding area and the fuse holding area. Compared with the prior art, the spot welding clamp can well position a fuse and a metal strip and adjust the height of a welding pin, thus improving spot welding quality, lowering welding defect rate, improving productivity and reducing cost. In addition, the invention also discloses a spot welding process using the spot welding clamp.

Abstract: Provided is an electrode (1) which has a double structure including Cu or a Cu alloy as an electrode body (2) and a core material (3) made of W, Mo, a W-based alloy, or a Mo-based alloy embedded in a surface of the electrode body (2) which is abutted against a material to be welded, the core material (3) being formed by using W, Mo, the W-based alloy, or the Mo-based alloy which is in the form of a fibrous structure extended by sintering, swaging, and annealing in an electrode axis direction, the fibrous structure having a horizontal cross-sectional average particle diameter of 50 ?m or more and an aspect ratio of 1.5 or more. The electrode (1) can be used as an inexpensive electrode obtained by suppressing particle dropping/attrition and defects in electrodes for spot welding, in which heat and pressure are applied repeatedly, stably enhancing durability.

Abstract: A method of repairing a bonded metallic structure having a first metallic member bonded to a second metallic member is provided. The method includes the steps of: A) forming a hole in at least one of the first metallic member and second metallic member, wherein said hole is sufficiently configured to receive a slug; B) inserting said slug into said hole; and C) passing electrical current through said slug of sufficient intensity to promote melting at the interface between the first metallic member, second metallic member, and said slug, thereby securing the first metallic member with respect to the second metallic member. Alternately, the method may include: D) positioning said slug near said hole; E) passing electrical current through said slug of sufficient intensity to promote arcing between said slug and the bonded metallic structure; and F) inserting said slug into said hole thereby securing the first metallic member with respect to the second metallic member.

Abstract: A method of welding two or more workpieces employing a motion-controlled electrode that reduces temperature and residual stresses at a workpiece-to-electrode interface is disclosed. During a first period of time, a first electrode force is applied to the workpieces to be welded, and a weld current is applied that causes heating of an associated workpiece-to-workpiece faying surface, the first electrode force being applied at a first electrode stroke. A temperature of the faying surface indicative of a weld nugget formation thereat is determined, and in response thereto the electrode force is reduced to a second level during a second period of time while maintaining a constant electrode stroke. During a third period of time, the electrode force is further reduced to a third level while simultaneously reducing the electrode stroke to a second level. Welding is stopped after the third period of time, resulting in a weld joint having reduced residual stresses and reduced likelihood of stress crack formation.

Abstract: A spot welding system including spot welding gun having a movable electrode driven by a servo motor, a counter electrode arranged facing it and with a multiarticulated robot, holding one of the welding workpiece and spot welding gun which moves welding workpiece and spot welding gun relative to each other and thereby make the movable electrode and the welding workpiece approach each other from a separated state or vice-versa, monitoring the current or torque of the servo motor, and detecting the surface position of the welding workpiece from the position of the movable electrode and the position of the multiarticulated robot when the trend of the current or torque changes. The precision of detection of the surface position of the welding workpiece by a movable electrode in a spot welding system can now be improved without lengthening the time required for detection of the surface position of the welding workpiece.

Abstract: Methods and systems for resistance spot welding using direct current micro pulses are described. One described method comprises comprising forming a weld joint by applying a plurality of direct current micro pulses to at least two pieces of materials through a first electrode and a second electrode.

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: A spot welding gun for resistance welding of workpieces, includes a base body and a bracket, in which electrode holders are arranged, the electrodes being in turn arranged in the holders. At least one electrode holder is fixed to an actuator that enables the electrode holder fixed thereto with the electrode to be displaced in longitudinal direction towards other electrodes. To protect the electrodes, a winding device with a band is arranged, the band being displaceably arranged between the contact surface of the electrode and the workpiece opposite the electrode. The winding device assigned to the displaceable electrode is connected to the displaceable electrode so that it moves at the same time as the electrode when the electrode is moved in longitudinal direction. The electrode holders and the electrodes have devices for guiding the band from the winding device axially along the electrode holders towards the electrode and vice versa.

Abstract: The invention relates to a spot welding cap changer (1) with a cap puller (2) and two cap magazines (3, 3A), the cap puller (2) having a gripper (20) with spring-loaded, pivotable jaws (21, 22), which in response to a turning and axial pulling-off movement detaches a spot welding cap (K) of a pincer spot welding head introduced into it from a shaft of the pincer welding head in such a way that it is clamped to prevent it twisting, and the cap magazines (3, 3A) holding spot welding caps respectively in a round cap carrier (31) such that they are circularly arranged in a directed and oriented manner and are respectively transported individually one after the other into an access position against a stop (32) by an advancing force (P).

Abstract: A supply chute 11 has a nut send-in port 14 at its upper end, and is composed of an inclined chute 12 inclined obliquely downward, and a curved chute 13 coupled to the lower end of the inclined chute 12 and curved like an arc obliquely downward. A nut support mechanism 40 is disposed at a nut send-out port 15 provided at a terminal end of the curved chute 13, for supporting the nuts 60 being forwarded so that their bonding side 62 may be in an oblique downward position nearly orthogonal to the axial line of a guide rod 20. The inclined chute 12, the curved chute 13, the guide rod 20, and driving means 25 for moving the guide rod 20 back and forth in an oblique downward direction are mounted on a stand 22 installed rotatably on a support member 33 by way of a horizontal support shaft 35, and the support member 33 is coupled and fixed to a main body arm 2 of the bonding machine 1.

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: There are provided a spot welding apparatus and a spot welding method. A workpiece is clamped between a combination of a second welding electrode and a receiving unit that abut against a thinner plate, and a first welding electrode that abuts against a second thicker plate, a pressure is applied to the workpiece by the first welding electrode, and a current is passed between the welding electrodes. Consequently, a satisfactory nugget is formed over from the thinner plate to the second thicker plate. Similarly, a workpiece is clamped between a combination of the first welding electrode and the receiving unit that abut against a thinner plate, and the second welding electrode that abuts against a second thicker plate, a pressure is applied to the workpiece by the second welding electrode. Consequently, a satisfactory nugget is formed over from the thinner plate to the second thicker plate.

Abstract: A resistance welding apparatus includes a welding gun having a first electrode tip serving as a first welding electrode, a second electrode tip serving as a second welding electrode, and a current branching electrode. The current branching electrode has an annular shape and is disposed in surrounding relation to the first electrode tip. The first electrode tip and the current branching electrode abut against a thinnest workpiece disposed on an outermost side of a stacked assembly that is resistance-welded by the resistance welding apparatus, and have opposite polarities to each other. When an electric current is passed from the first electrode tip to the second electrode tip and through the stacked assembly, a branched electric current flows from the first electrode tip to the current branching electrode.

Abstract: A multiple welding gun system includes a plurality of welding guns, simultaneously performing welding operations, mounted to a robot arm of a welding robot and a pitch changing device as a space adjusting device disposed between the plurality of welding guns. The pitch changing device is configured to change a gun pitch so as to adjust a space between the welding guns by rotating one of the welding guns relative to other one of the welding guns to thereby move the welding guns closer to or separate from each other.

Abstract: A weld data management and monitoring system that supports weld data trend analysis. Weld data is collected for each weld operation and a trend index equation is applied to the data to calculate a composite number for the operation. The composite numbers for numerous welds may be plotted and analyzed to detect and evaluate weld trends over a specified period of time. In an example embodiment, the trend index equation uses the weld heat input, current, resistance, and time values to calculate the composite number. Trend data may be analyzed to identify a time when variances, whether within or outside specified tolerances, occurred. The ability to detect and analyze variances in weld operation data during a specified period of time may assist the manufacturer in identifying and resolving problems related to the weld equipment as well as other manufacturing processes or operations that may have caused variances in weld operations.

Abstract: A welding structural part 1 is manufactured by overlapping the surfaces of steel sheets 2, and forming a weld zone by spot welding. The weld zone 3 includes: a weld nugget 4; and a heat affected zone 5 surrounding the weld nugget 4, wherein the hardness in the weld zone increases along an exterior region 6 of the heat affected zone 5 toward the heat affected zone 5, and then decreases along the heat affected zone 5 toward the central region of the weld nugget 4. In the boundary region between the weld nugget 4 and the heat affected zone 5, the weld nugget 4 may have a convex portion 4A bulging into the heat affected zone 5 along the overlapped portion. The steel sheets 2 contain carbon in 0.15 mass % or more.

Abstract: Spot welding tongs for robotic applications in resistance welding of workpieces, in particular sheets, comprise tong arms, mounted such as to pivot on a base body. These tongs which may be adjusted and to which electrode holders for the electrodes are fixed and a winding device with a pay-out roller and a wind-in roller, for the winding in and out of a strip to protect at least one electrode. These spot welding tongs may be produced, in which access is not seriously affected and with a very simple and compact construction, whereby the pay-out roller and the wind-in roller of the winding device are arranged on the base body, or the tongs arm and at least one guide groove, for guiding the strip, is arranged in the tongs arm and/or the electrode holder.

Abstract: An electrode unit of a spot welding machine in which a recessed fitting portion having a circular shape in section is formed in a surface of a projecting portion of an electrode holder. A first groove is formed in an inner peripheral surface of the recessed fitting portion. A cooling water passage continuous to the recessed fitting portion is formed in the electrode holder. A columnar fitting portion is formed in a base end of the abutting portion of the electrode. A second groove is formed in an outer peripheral surface of the fitting portion. The fitting portion is inserted in the recessed fitting portion. An O ring is fitted in the first groove and the second groove. Then the electrode is attached to the projecting portion. A cooling water circulated in the cooling water passage cools down the electrode and the projecting portion.