> Overview

„Optimum reliability, outstanding precision“

New welding control system B 20K

As a unique system anywhere in the world, the B 20K welding control system opens up new dimensions, in particular in the field of resistance welding. This is due to the active power supply module, which provides reliable protection against power fluctuations, as well as the new NC linear actuator which now welds the strip and contact material to each other in one precisely controllable linear movement.

The B 20K welding control system has been available since the middle of 2018 and has been warmly welcomed by users thanks to its many unparalleled features and functions. These include, for example, the five measurement channels that are integrated as standard. These capture, analyze and monitor all the relevant parameters and also, as of now, determine the resistance profile during welding. Another impressive feature lies in the fact that in the B 20K, a single inverter provides all the required power values from 70 to 220 kilovolt-amperes. As a result, time-consuming conversion or replacement operations are no longer needed. At the same time, the B 20K excels in practice through its outstanding ergonomics, ease of navigation and compact screen information.

Reliable and economical

The B 20K’s active power supply module is particularly valuable. This patented mechanism securely and reliably protects the system against power fluctuations. As a result, short-term drops in the mains power supply of just a few milliseconds due to other high energy consumers no longer have any effect on the welding process. This is achieved by raising the internal supply voltage at the start of the welding process and then lowering it again in a linear fashion until it reaches the required level. The increased supply voltage is stored in the buffer capacitor. Like a battery, this buffer then outputs the power needed for welding, which therefore no longer has to be drawn from the electricity from the mains power supply. As a result, this reduces the short-term current load during welding by approximately 50 percent – another benefit of the active power supply module. At the same time, the recharging of the buffer capacity extends the current consumption time to approximately twice the welding time.

The new NC linear actuator now makes it possible to weld the strip and contact material together in a precisely controllable linear movement. In addition, the welding current no longer has any impact on the welding force.

Linear welding movement

With the patented NC linear actuator, it has also been possible to develop another unique innovation for the B 20K. The actuator is a controllable unit that now welds the strip to the contact material in a linear movement. At the same time, the force it applies can be precisely controlled throughout the entire welding process. In this way, the NC linear actuator complements the B 20K’s conventional welding electrode – and therefore also the previous motion profile of the electrodes, which traveled along an arc trajectory around a center of motion. The current conduction mechanism is integrated in the actuator and is directly connected to the transformer. This combination has a partially flexible design in order to permit repositioning during the welding process. As a result, the force of the welding current, which normally presses the electrode arms away from one another, is applied inside the actuator and therefore no longer has any impact on the welding force. The control of the linear motors is also influenced by the arrangement of the conductors and not by the magnetic force of the welding current.

Constant, high precision

Thanks to the possibility of controlling the linear actuator, the closing movement and force can be set precisely and reproducibly. Another important advantage lies in the fact that the force can be precisely increased and reduced during welding in a way that is synchronized with the welding profile. This permits extended process control. The design of the actuator is rounded off by the presence of additional NC axes for feeding the welding material, cutting it and transporting the contacts. As a result, a fully-featured, NC-based control mechanism is available as of now and makes possible new welding applications by offering unparalleled precision and perfect handling.

Martin Ott
Head of Welding Department

Tel.: +49(0)8368/18-340



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