A spot-welding electrode cap extends along a longitudinal axis and has an end side with a central cap contact surface and with a transition section connecting directly radially and tangentially to the cap contact surface. The transition section is configured to be convexly curved with a radially outwardly continuously increasing curvature.

A welding assembly may include a current generator, a first electrode electrically coupled to the current generator, the first electrode including a first engagement surface, a second electrode electrically coupled to the current generator, the second electrode including a second engagement surface and a width-determining fixture positioned between the first electrode and the second electrode to define a welding volume.

Provided is an electric resistance welding electrode, which comprises an insulated cylinder, an electrode slidably inserted into the insulated cylinder, an urging member configured to apply an advance force to the insulated cylinder, and a stopper configured to set an advance distance of an insulated end surface of the insulated cylinder with respect to an pressing surface of the electrode to a predetermined distance. A receiving recessed portion for receiving a component is defined by the pressing surface retreated by the predetermined distance with respect to the insulated end surface and an inner surface of the insulated cylinder. The electric resistance welding electrode performs welding in one of welding modes consisting of a component welding mode and a spot welding mode.

The present disclosure provides a method of resistance spot welding that can inhibit Liquid Metal Embrittlement-induced cracking in zinc-coated steel plates irrespective of the degrees of tensile strength. One aspect of the present disclosure provides a method of resistance spot welding. The method comprises welding a workpiece with a resistance spot welding apparatus. The workpiece includes two or more steel plates in an overlapping state. The two or more steel plates include at least one steel plate coated with zinc. The welding includes welding while compressing a high-tensile steel plate among the two or more steel plates in a direction intersecting a direction of a thickness of the high-tensile steel plate. The high-tensile steel plate has a tensile strength higher than a tensile strength of another steel plate among the two or more steel plates.

There is provided a welded structure that can reduce fractures at welded portions. The welded structure includes two or three steel sheets and a lapped portion in which the steel sheets are overlapped and joined by spot welding at a plurality of locations, the welded structure including a spot weld portion, and, when a diameter of a nugget is d.sub.ng (mm), a tip diameter of an electrode used by the spot welding is d (mm), and an average thickness per steel sheet of the steel sheets at the lapped portion is t.sub.ave (mm), the spot weld portion satisfies d.sub.ng>d(t.sub.ave).sup.1/2 when 0.5 mmt.sub.ave<1.1 mm and d.sub.ng>1.05d when 1.1 mmt.sub.ave2.6 mm, in accordance with the average thickness t.sub.ave (mm).

A vibration spot welding device according to an exemplary embodiment of the present invention may include a first welding tip that is disposed to contact one side surface of metal plates that are overlapped, and a second welding tip that is disposed to contact the other side surface of the metal plates corresponding to the first welding tip, wherein the second welding tip includes a first electrode portion that is disposed to contact the metal plate so as to transmit a current thereto, and a second electrode portion that is disposed to contact the metal plate so as to receive the current that is transferred from the first electrode portion through the metal plate.

A hybrid electrode for resistance spot welding and a method of resistance welding are provided. The hybrid electrode comprises a pin and a collar member. The pin comprises an electrically conductive material and a pin contact surface. The collar member comprises a material that is at least one of less electrically conductive than the electrically conductive material of the pin and less thermally conductive than the electrically conductive material of the pin. The collar member comprises a collar member contact surface, and defines an inner cavity and a longitudinal axis. The pin is at least partially disposed in the inner cavity and the pin contact surface extends away from the collar member and is offset a distance along the longitudinal axis from the collar member contact surface.

An electrode tip for resistance spot welding includes a main body with tip and base portions. The tip portion has a bottomed and substantially cylindrical shape. The base portion has a substantially cylindrical shape and merges into the tip portion. The main body is made of a copper alloy such as chromium copper. The tip portion has a bottom part and a barrel part. The bottom part has a pressure-contact surface that is not recessed with respect to a workpiece to be pressed. The barrel part has a substantially cylindrical shape and merges into the bottom part. The electrode tip may have an inner diameter ratio (inner diameter of the barrel part to an outer diameter of the base portion) of 0.4 to 0.6, and may also have a bottom thickness ratio (thickness of the bottom part to the outer diameter of the base portion) of 0.15 to 0.5.

One aspect of the present disclosure is a resistance spot welding apparatus for welding a workpiece made of layered metallic plates. The resistance spot welding apparatus includes a first electrode; a second electrode arranged such that the workpiece is interposed between the first electrode and the second electrode; and a pressure mechanism that applies pressure to the first electrode towards the first metallic plate by air. The pressure mechanism includes a piston coupled to the first electrode; a cylinder having an inner space that accommodates the piston; a first ventilation unit that supplies the inner space with air for applying pressure to the first electrode; and a second ventilation unit that discharges air from the inner space as pressure is applied to the first electrode. At least one of the first ventilation unit or the second ventilation unit includes two or more air passages that communicate with the inner space.

A resistance welding device. The device includes: a clamp intended to support an arm including a first part supporting a stationary electrode and a second part supporting a translationally movable electrode, the electrodes being intended to be passed through by an electrical current and to clamp metal elements in order to weld them The movable electrode is configured to move between a working position, wherein the electrodes clamp the metal elements to be welded, and two opening positions making it possible to insert, between the electrodes disposed opposite one another, the metal elements to be welded.