Merrick Welding International, Inc.

Crc Welding Systems, Inc.

Vanderbilt University

Westinghouse Electric Corporation

The Merrick Corporation

George E Cook

George J Merrick

Donald D Modglin

Alvin M Strauss

Daniel A Hartman

David R Delapp

David H Lammlein

Paul Fleming

Don Mitchell Wilkes

A Michael Wells

Urban A Schneider

Willibald R Rosenberger

An apparatus and computer program are disclosed for processing at least one workpiece using a rotary tool with rotating member for contacting and processing the workpiece. The methods include oscillating the rotary tool laterally with respect to a selected propagation path for the rotating member with respect to the workpiece to define an oscillation path for the rotating member. The methods further include obtaining force signals or parameters related to the force experienced by the rotary tool at least while the rotating member is disposed at the extremes of the oscillation. The force signals or parameters associated with the extremes can then be analyzed to determine a lateral position of the selected path with respect to a target path and a lateral offset value can be determined based on the lateral position. The lateral distance between the selected path and the target path can be decreased based on the lateral offset value.

Lateral position detection and control for friction stir systems

Friction stir methods are disclosed for processing at least one workpiece using a rotary tool with rotating member for contacting and processing the workpiece. The methods include oscillating the rotary tool laterally with respect to a selected propagation path for the rotating member with respect to the workpiece to define an oscillation path for the rotating member. The methods further include obtaining force signals or parameters related to the force experienced by the rotary tool at least while the rotating member is disposed at the extremes of the oscillation. The force signals or parameters associated with the extremes can then be analyzed to determine a lateral position of the selected path with respect to a target path and a lateral offset value can be determined based on the lateral position. The lateral distance between the selected path and the target path can be decreased based on the lateral offset value.

A friction stir system for processing at least a first workpiece includes a spindle actuator coupled to a rotary tool comprising a rotating member for contacting and processing the first workpiece. A detection system is provided for obtaining information related to a lateral alignment of the rotating member. The detection system comprises at least one sensor for measuring a force experienced by the rotary tool or a parameter related to the force experienced by the rotary tool during processing, wherein the sensor provides sensor signals. A signal processing system is coupled to receive and analyze the sensor signals and determine a lateral alignment of the rotating member relative to a selected lateral position, a selected path, or a direction to decrease a lateral distance relative to the selected lateral position or selected path. In one embodiment, the friction stir system can be embodied as a closed loop tracking system, such as a robot-based tracked friction stir welding (FSW) or friction stir processing (FSP) system.

Method and apparatus for welding edge joints such as turbine blades and the like, including adaptive tracking circuitry for maintaining the center of oscillation of the welding electrode substantially aligned with the center of the workpiece as the electrode is moved along the workpiece, and means for adjusting welding parameters such as welding current to prevent melt over of the edge and wirefeed rate to control overlay height as the welding electrode approaches to within a predetermined distance from the edge of the workpiece. The disclosed embodiment samples the arc signal, processes the arc signal to remove undesirable noise components, uses the processed signal to adaptively position the electrode with respect to the workpiece, and controls the welding parameters related to overlay height when the sensed position of the electrode reaches a predetermined distance from the edge of the workpiece.

Adaptive control system for welding inverted seams

Apparatus and method for sensing the topography of a workpiece with an electrical arc by measuring a parameter of the electrical arc signal as an electrode is scanned across the surface of the workpiece by a tool manipulator such as a multi-axis robot arm, and processing the measured arc signal in order to derive the three-dimensional topography. The apparatus includes a digital microcomputer which samples the arc signal, stores a plurality of samples in computer memory, computes the average of a predetermined number of samples, and provides correction factors to the host computer of the robot manipulator so that the electrode or a tool carried by the robot can be adaptively positioned. The apparatus senses such features of the workpiece as holes, edges, and slopes of a given magnitude, and passes the location of these features to the host computer for appropriate corrective action. The system provides vertical correction factors as well as workpiece scanning correction factors so that the host can adaptively adjust the position of the electrode or of a separate tool with respect to the workpiece.

Apparatus and method for sensing a workpiece with an electrical arc

A template-matching adaptive control system for welding comprising noncontacting means for sensing the lateral profile of a weld joint while the welding electrode moves laterally across the joint, means for comparing the sensed lateral profile to a predetermined reference profile or 'template', and means for adjusting a welding parameter, such as the center of oscillation for tracking, the width of oscillation, and constant fill control, in response to the results of the comparison. The comparison between the sensed lateral profile and the template is based upon a mathematical criterion of the degree of match therebetween. One disclosed embodiment performs control based upon finding the closest match between the sensed lateral profile and a plurality of different templates. Another embodiment performs control by making adjustments related to the value of the mathematical criterion. The disclosed embodiments employ programmed microprocessers to accomplish the template matching. The system can adapt to changes in direction of the weld seam as well as changes in the width and shape of the profile of the weld seam.

Template-matching adaptive control system for welding

An adaptive control system for welding which senses the lateral profile of a weld joint while the welding electrode moves laterally across the joint, compares a first portion of the sensed lateral profile to a second portion of the sensed lateral profile, and then adjusts a welding parameter, such as the center of oscillation for tracking, the width of oscillation, and constant fill control, in response to the results of the comparison. One disclosed signal processing technique matches an average of data samples for the left portion of the weld seam to an average of data samples for the right portion. Another disclosed technique involves comparing an integrated signal corresponding to the leftward portion of the sensed lateral profile to an integrated signal corresponding to the rightward portion. Another disclosed technique involves comparing an integrated sensed profile signal to a predetermined reference value which is based upon a reference signal. The reference signal comprises data representative of the prior history of the weld joint. The disclosed embodiments employ programmed microprocessors to provide horizontal cross-seam control and process the arc signal to remove undesirable noise. The system can adapt to changes in direction of the weld seam as well as changes in the width and shape of the profile of the weld seam.

Sidewall-matching adaptive control system for welding

Apparatus for manipulating a welding torch independently along two axes. A torch support is provided to carry a welding torch or the like, and a motor is operatively coupled to position the torch support along a first path of travel relative to the weld joint. Another motor is operatively coupled to position the torch along a second path of travel orthogonal to the first path of travel.

Welding torch oscillating mechanical apparatus

Apparatus for tracking a welding electrode (22) within a weld groove (12). As the welding arc struck between the electrode (22) and the workpiece (16) is oscillated laterally (14) within the groove means (28 and 30) are provided for supplying an indication of both the voltage drop between the electrode and the side wall of the groove as the arc approaches the side wall, and the width of the excursion of the arc from the center of oscillation to the point where the voltage is measured. The center of oscillation is then adjusted as a function of the measured width and voltage.

Weld tracking/electronic arc sensing system

Apparatus and method for rapid and automatic welding of joints which interconnect sections of pipe, and in particular oil or gas transmission pipe. The system includes at least one torch transport assembly which simultaneously moves one or more welding torches along a path parallel to the joint being welded. Selected operating parameters such as preheating power for the filler wire, of each welding torch are adjusted to accurately position each torch with respect to the joint, and to repeatably provide programmed welding parameters resulting in a uniform joint weld. The present system is disclosed in the context of hot-wire gas-tungsten arc welding torches.

Automatic pipe welding system

Apparatus for rapid and automatic welding of joints which interconnect sections of pipe, and in particular oil or gas transmission pipe. The system includes at least one torch transport assembly which simultaneously moves a plural number of welding torches along a path parallel to the pipe joint being welded. The torch transport assembly includes track segments which surround circumferential portions of the pipe joint, with a welding torch carrier and multiple torches being independently movable along each track segment. The torch transport assembly is mounted on a support apparatus which is rigidly clamped to the pipe sections during welding, and which permits the torch transport assembly to be rapidly positioned in rough alignment with a pipe joint. The torch transport assembly and selected operating parameters of each welding torch are adjusted to accurately position each torch with respect to the pipe joint, and to repeatably provide programmed welding parameters resulting in a uniform pipe joint weld. The present system is disclosed in the context of hot-wire gas-tungsten arc welding torches, and in the operating environment of out-of-position joint welding.

Welding torch oscillation apparatus

Clamping apparatus for welding circumferential articles

A welding torch assembly including a torch base, and a torch body which can be rapidly removed from the torch base and replaced without the use of tools, and without separately disconnecting welding current, coolant, or shielding gas lines.

Welding torch and supporting apparatus

Filler wire spool support for welding applications in which filler wire is supplied to a weld puddle. The present spool support apparatus is readily manipulated to replace the filler wire spool without the use of tools.

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Brentwood, TN, United States of America

George E Cook