Reis Robotics inspires the field of resistance welding of sheet metals with innovative seam welding tongs, patent pending, tongs which for the first time are servo-motorized and synchronized directly with a robot movement. Advantages are better electric contact, less wear of rollers, welding of smaller component radii and better cooling. Thus again, Reis demonstrates how even established technologies can be improved considerably more by innovative approach.

"Seam welding tongs have been operated stationary or guided by a robot by 'dragging' so far, but now we implemented the servo-motorized movement in practical use for the first time and synchronized it with the robot movement", says Stefan Seiler, division manager for sales of automated welding systems at Reis Robotics. "Together with the specialists from Elektro-Schweißtechnik-Dresden GmbH we developed welding tongs for seam welding which are not only very compact, but is also actively driven by a servo-motor. This idea is subject to a patent application."

The automated seam welding so far was also associated with some disadvantages. The rolling welding electrodes could 'race' on the workpiece due to the drive not being synchronized, because robot and welding tongs did not communicate. Due to this slip there will be higher wear and worse seam quality due to insufficient contact. Very large rollers were used to obtain higher service lives of the electrodes. These rollers, however, cannot follow the narrow radii or S-shaped contours. With this old procedure individual adjustment of parameters – for example the advance rate – for every single welding process or any material combination was not possible. This system compensates for component tolerances automatically.

The roller drive now is a further axis of the robot, because its speed is synchronized via servo-motors and corresponding sensors directly via the robot control with its movement in space, or in other words: The movement of the rollers now reflects the actual speed of the welding process. This increases the service life of the electrodes considerably. Furthermore, the electrodes could be dimensioned smaller because of less wear. Thus, very narrow radii are possible for which this welding procedure could not be used in the past. The more compact electrodes now are water-cooled until immediately before the welding process.

All in all the pathbreaking innovation from Reis excels with better seam quality and more flexible applications are possible with different materials. The higher service lives of the electrodes in all result in increased efficiency.

This pathbreaking idea received the Euroblech Award.

The optimizer function of the robot control ROBOTstarV-PCX optimizes the programmed robot movements such way that the machine reserves regarding amplifier current and motor moment will be utilized to an optimum, without overloading the drive components. Optimization is effected online during the robot movement.

A mathematical robot model filed in the control continuously determines the maximum available motor moment depending on the robot axes position and the payload. Then the acceleration parameters are adapted such way that the available drive capacity will be utilized to an optimum. The axes speeds always remain under control of theprogrammer as they normally represent a quality determining parameter in a production process. The optimizer guarantees a time optimum movement in any operating mode of the robot. Thus, it is possible to reduce the cycle times by up to 30 percent.

The robot model considers alternating payloads and also allows the integration of additional loads onto different robot axes. A typical application is palletizing. The optimizer can utilize its complete potential with permanent load changes between palletizing and idle running and the constantly changing palletizing movements.

The degree of optimization can be set optionally at random positions in the program sequence. This allows a smooth movement during transportation of sensitive workpieces or liquid materials and a quick movement during idle running.

The Reis Optimizer only engages the traversing profile of a programmed movement. The path itself remains as the user did program it. There is no danger of collision due to modified robot movements.