A sliding electric contact device for welding head for roller welding machines, having comprises a bimetallic plate adapted to be fixed to a shaft of a welding head, having a protection base composed of a first metal, defining a first face destined to abut against an end surface of the shaft, and a sliding disk composed of a second metal softer than the first metal, defining a second sliding electric contact face; a composite current-carrying block, having a plait of electrical wires, an internal support made of metal, pushed against the sliding disk for realizing with the sliding disk a sliding electric contact, first means adapted to fix firmly a central portion of the plait to the inner support, second current-carrying means adapted to fix firmly a peripheral portion of the plait to current terminals of a stator of the welding head. A welding head having the sliding electric contact device and a related roller welding machine are also disclosed.

This seam-welding device carries out seam welding while repeating one cycle comprising a melting period, an interruption period, and a heating period implemented either before or after the interruption period. A welding current is applied between a pair of roller electrodes so as to form a welded part between workpieces during the melting period, the application of the current between the roller electrode pair is interrupted so as to solidify the welded part during the interruption period, and a heating current smaller than the welding current is applied between the roller electrode pair so as to heat the laminated body within a solidification temperature range of the welded part during the heating period. Consequently, even when the welding speed is increased, formation of cracks and spatter is effectively suppressed such that a high-quality joined product is obtained.

This seam-welding device carries out seam welding while repeating one cycle comprising a melting period, an interruption period, and a heating period implemented either before or after the interruption period. A welding current is applied between a pair of roller electrodes so as to form a welded part between workpieces during the melting period, the application of the current between the roller electrode pair is interrupted so as to solidify the welded part during the interruption period, and a heating current smaller than the welding current is applied between the roller electrode pair so as to heat the laminated body within a solidification temperature range of the welded part during the heating period. Consequently, even when the welding speed is increased, formation of cracks and spatter is effectively suppressed such that a high-quality joined product is obtained.

A second joining flange formed along an edge of a second panel and a third joining flange formed along an edge of a third panel are superimposed on a first joining flange formed along an edge of a first panel, a seam weld is made in a section in which the first joining flange and the second joining flange form two layers and a section in which the first joining flange and the third joining flange form two layers, and a spot weld is made in a section in which the first joining flange, the second joining flange and the third joining flange form three layers. Such structure enhances production efficiency by increasing welding speed, and facilitates spot welding in the section having three layers, for which seam welding is difficult due to the large number of superimposed sheets, thereby enhancing strength against peel-off.

A welding device may include a weld head. A welding device may include a positive welding electrode connected to the weld head. A welding device may include a positive electromagnetic actuator connected to the positive welding electrode. A welding device may include a positive position sensor configured to detect a position of the positive welding electrode. A welding device may include a positive force sensor configured to detect a force applied by the positive welding electrode. A welding device may include a negative welding electrode connected to the weld head. A welding device may include a negative electromagnetic actuator connected to the negative welding electrode. A welding device may include a negative position sensor configured to detect a position of the negative welding electrode. A welding device may include a negative force sensor configured to detect a force applied by the negative welding electrode.

A welding device may include a weld head. A welding device may include a positive welding electrode connected to the weld head. A welding device may include a positive electromagnetic actuator connected to the positive welding electrode. A welding device may include a positive position sensor configured to detect a position of the positive welding electrode. A welding device may include a positive force sensor configured to detect a force applied by the positive welding electrode. A welding device may include a negative welding electrode connected to the weld head. A welding device may include a negative electromagnetic actuator connected to the negative welding electrode. A welding device may include a negative position sensor configured to detect a position of the negative welding electrode. A welding device may include a negative force sensor configured to detect a force applied by the negative welding electrode.

A manufacturing method of an optical module including a package and lid, the package having an opening to be sealed with the lid. The manufacturing method includes placing the lid on the package so that the lid covers the opening; putting a metal block on the lid, the metal block having a first surface touching a top surface of the lid; welding the lid to the package using a seam welding machine, the first surface of the metal block touching the top surface of the lid during the welding, the metal block being configured not to interfere the seam welding machine; and detaching the metal block from the lid.

Provided is a welding monitoring apparatus that monitors a welding state of a V-convergence region in which a strip-shaped metal sheet is converged in a V-shape, when the metal sheet is cylindrically formed while being conveyed, and both side edges of the metal sheet are heated and melted in a manner of being butted each other while being converged in the V-shape, such that an electric resistance welded steel pipe is manufactured. This welding monitoring apparatus includes an image capturing unit that captures images of a region including the V-convergence region in time series; and an image processing unit that extracts a welding point based on the images captured in time series and detects the presence or absence and a position of irregular arcing at the welding point or on an upstream side of the welding point.

A method for cleaning the surface of a metal wire (2) or a metal strip, in particular of a metal wire (2) or a metal strip used as an intermediate electrode of a roll seam welding machine, wherein the metal wire (2) or the metal strip is guided under tensile stress in the longitudinal direction of the wire or the strip along a plurality of wiping bodies (4) arranged at a distance one behind the other in the longitudinal direction of the wire or the strip, in such a way that the wire or the strip sections (5a-5g) each lying between two successive wiping bodies (4) together form a bow-shaped wire section. It has turned out that this enables an intensive and reliable cleaning with constant cleaning quality.

An electrode tab welding device according to an embodiment of the present invention may weld a plurality of electrode tabs of an electrode assembly. The electrode tab welding device may include: a pair of tab guides that gather the plurality of electrode tabs; a pair of aligning rollers that rotate in a direction, in which the outermost electrode tab is pushed toward the electrode assembly, while pressing the plurality of electrode tabs gathered by the pair of tab guides; and a welding part that welds the plurality of electrode tabs, which are aligned by the pair of aligning rollers, to each other.