Automatic joint tracking for CNC-programmed electron beam welding
In an effort to provide a means for actively maintaining precise alignment during an entire welding procedure, various types of contact and non-contact joint sensing and tracking methods have been investigated over the years. A stylus riding in the groove or a cam follower running along a machined reference surface that parallels the groove, coupled to a transducer for producing a signal indicative of seam path runout, is one method that has been investigated. Another is the employment of light-sensitive devices, used in both a comparative and a discerning fashion to produce a signal indicative of beam-to-joint alignment. Also, electronic detectors that monitor the magnitude of either electron or x-ray emission coming back from a workpiece and produce a signal indicative of beam-to-joint alignment deviations have been investigated. Of the various methods tried, the one which has proved to be ideal for use in joint sensing and tracking during EB welding is that of monitoring the ''secondary'' electron backflow that results when a workpiece is bombarded with a beam of ''primary'' electrons. This is because the primary electron beam producing this secondary electron backflow is the welding beam itself. Since the welding beam becomes the means for measuring joint location, the technique of sensing secondary electron backflow automatically provides a direct correlation between the actual welding beam position and the joint location measured. Thus, any need for calibrating an auxiliary joint location device to actual welding beam position is eliminated. In addition, this method is least affected by the high amount of vapor and spatter generated during welding. In this article, a system employing Secondary Electron Emission Sensing (SEES) to provide an on-line (''realtime''), truly automatic joint tracking capability will be discussed.
- Research Organization:
- Leybold-Heraeus Vacuum Systems, Inc., Enfield, Conn.
- OSTI ID:
- 5091147
- Journal Information:
- Weld. J. (Miami); (United States), Vol. 64:8
- Country of Publication:
- United States
- Language:
- English
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Apparatus for maintaining alignment of a shrinking weld joint in an electron-beam welding operation
Apparatus for maintaining aligment of a shrinking weld joint in an electron-beam welding operation
Related Subjects
ELECTRON BEAM WELDING
AUTOMATION
ENERGY EFFICIENCY
WELDING MACHINES
COMPUTERIZED CONTROL SYSTEMS
ORIENTATION
BEAM DYNAMICS
CLOSED-LOOP CONTROL
FEEDBACK
FOCUSING
POWER DENSITY
RADIATION DETECTION
WELDED JOINTS
CONTROL
CONTROL SYSTEMS
DETECTION
EFFICIENCY
FABRICATION
JOINING
JOINTS
WELDING
320303* - Energy Conservation
Consumption
& Utilization- Industrial & Agricultural Processes- Equipment & Processes