The present application discloses a system and method for an automated or semi-automated welding operation with minimal input from an operator on a workpiece using a programmable logic controller (PLC) communicatively coupled to a non-transitive memory device and a welding machine. The present application uses the PLC to obtain information from a technical drawing stored in the memory device and default values of welding parameters for the welding operation. The PLC calculates a first rotational speed and performs the welding operation on the first portion of the workpiece based on the first instruction received from the PLC. If the welding parameters need to be adjusted during the welding operation, new welding parameters are obtained from the technical drawing and the PLC re-calculates a second rotational speed for the workpiece and performs the welding operation based on the second instruction received from the PLC.

The present invention provides an arc welding control system and method capable of simultaneously, sophisticatedly performing a weaving width control operation and a torch height control operation. Influence ratios (.sub.w and .sub.z) of influences of a torch height deviation (P.sub.h) and a groove wall distance deviation (P.sub.d) with respect to a manipulated variable (w) of a weaving width and a manipulated variable (z) of a torch height are set in accordance with a groove angle () of a workpiece (5). A calculation unit (21) calculates the manipulated variables (z and w) of actuators (13 and 14) regarding the torch height and the weaving width such that the influence ratios (.sub.w and .sub.z) become large as the groove angle () becomes large.

An arc welder produces a weave pattern between workpieces. Each weld run comprises a center portion including a joining region between the workpieces and edge regions spaced apart from the joining region. The welder includes a power source that provides a welding waveform to a welding electrode to generate an arc to achieve a desired heat for welding, a welding torch, and an oscillator for oscillating the torch between the welding edge regions. A controller causes the power source to operate in a first mode utilizing a first waveform during welding within the joining region, and in a second mode using a second waveform, having a greater positive component than the first waveform, during welding within the edge regions. The controller determines a stickout value based on the first waveform but not the second waveform, and performs seam tracking based the second waveform but not the first waveform.

A welding apparatus comprising a first fixing plate and a second fixing plate arranged at an interval; a gas-electric slip ring is connected to the side of the first fixing plate facing the second fixing plate; a hollow shaft drive unit is connected to the side of the second fixing plate facing the first fixing plate; a conductive link is connected to the hollow shaft drive unit and passes through the second fixing plate; a curved conductive nozzle is connected to the conductive link on the outer side of the second fixing plate; and a plurality of support rods are uniformly distributed around the rotational axial direction of the hollow shaft drive unit, and are respectively connected to the first fixing plate and the second fixing plate; the hollow shaft drive unit drives the conductive link to rotate, and the conductive link drives the curved conductive nozzle to oscillate.

The object of the invention is a method and a device for making a pipe T-branch by connecting the shaped end of a branch pipe with internal welding to the edges of a hole in a main pipe. The hole in the main pipe (T) and the arcs corresponding to the main pipe at the end of the branch pipe (P) are cut mechanically by removing one solid part from the hole and two (22) solid parts from the end of the branch pipe in a dry mechanical process, wherein the cleanliness of the joint areas remains suitable for welding. The shaped end of the branch pipe (P) is placed around the hole in the main pipe and the joint seam (21) between the pipes is welded by internal welding without the use of a welding filler. A suitable branching hole is made by punching tangentially from the side of the main pipe such that the tangent of the pipe, which is parallel to the direction of movement of the punch tool, is located inside the punch tool (1).

A welding parameter derivation device of a welding machine having a torch and a weaving mechanism derives welding parameters in accordance with the cross-sectional shape of a weld portion of a new base metal. A database stores welding parameter data, and a welding parameter computation unit computes welding parameters for the shape of a groove or joint of a new base metal. Based on past welding parameter data for a shape similar to that of a groove or joint of a new base metal, and input data pertaining to the specifications of the welding machine, the computation unit derives welding parameter data for the new base metal, taking into account a parameter of the cross-sectional area of the weld portion formed on the new base metal, the bead height of the weld portion, the quantity of heat inputted to the new base metal, and a torch weaving parameter.

A system and method is provided in which a welding system modulates the heat input into a weld joint during welding by changing between a high heat input welding waveform and a low heat input welding waveform. The system can utilize detected weld joint geometry and thickness to vary the utilization of the high heat and low heat waveform portions to change the weld bead profile during welding. Additionally, the wire feed speed is changed with the changes between the high heat input and low heat input portions of the welding waveform.

An arc sensor adjustment device and adjustment method for carrying out highly-accurate copying control. A welding system includes a welding torch, a welding power source that supplies power to the welding torch, a robot and a robot controller that cause the welding torch to oscillate, and an arc sensor that obtains a welding current or a welding voltage generated during welding while oscillating the welding torch. The arc sensor obtains a welding current or a welding voltage generated during calibration, in which welding is carried out while oscillating the welding torch in an up-down direction, calculates, on the basis of the obtained welding current or welding voltage, a correction amount for the position of the welding torch during welding carried out while oscillating the welding torch in a left-right direction, and applies the calculated correction amount to copying control.

To provide an arc welding robot system that displays a current waveform graphically during arc welding and realizes parameter adjustment on a display screen. An arc welding robot system comprises a robot controller and a teaching operation terminal. The robot controller comprises: an arc sensor; and a welding current storage unit that stores the current value of a welding current detected by the arc sensor during implementation of the arc welding. The teaching operation terminal comprises: a control unit; and a display on which data is displayed. The control unit comprises: a welding current display unit that displays the current value and the waveform of the welding current in any weaving cycle on the display; a sampling current area display unit that displays a sampling current area on the display; and a current waveform display shift unit that shifts the waveform of the welding current in a temporal axis direction on the display unit.

A welding system that, using a junction at which a standing plate and a bottom plate meet as a welding line, makes an electrode weave centered on the welding line and thereby welds along the welding line. In this welding system, control is performed such that the arc voltage at a standing-plate-side weaving edge is equal to or less than the arc voltage at a welding-line center position, such that the arc voltage at a bottom-plate-side weaving edge becomes equal to or greater than the arc voltage at the welding-line center position, and such that the arc voltage at the standing-plate-side weaving edge becomes lower than the arc voltage at the bottom-plate-side weaving edge. The system can suppress occurrence of inferior bead appearance and of welding defects in horizontal fillet welding.