High-Performance Portfolio for Precision Welding Tasks

For the precision welding of small parts in the metal and electrical industries, Bosch Rexroth has developed the PXC7100—a particularly cost-effective control solution for resistance welding. In addition to welding tasks in sensor technology and battery manufacturing, it is primarily used for so-called "compacting" applications. In this context—unlike ultrasonic welding—resistance welding can be used to join or compact coated stranded wires. With the KWZ-Splice from Rexroth’s Authorized Partner KombiTec, users now also have access to another innovative compacting tool compatible with the Rexroth control system.

Bosch Rexroth developed the economical PXC7100 precision welding controller for resistance welding specifically for applications involving extremely low currents—such as the compacting of micro-strands, the contacting of sensors, or the welding of batteries. Unlike ultrasonic welding, resistance welding allows for the extension or compacting of coated stranded wires. This capability is particularly important in many electronics applications, for instance, where tinned wires are used to provide corrosion protection.

As an integral part of the PRI-web user interface, a setup wizard facilitates the rapid commissioning of the PXC7100. When using the optional MGD module (Measuring-Gun-Data module), only a single bus cable is required for all signal cables connecting to the welding controller, thereby significantly reducing wiring complexity. The MGD module digitizes all analog sensor signals and process data directly at the weld head (e.g., force signals, position signals, current signals, and transformer data). These pre-processed data are transmitted in real time (at a 1 kHz clock rate) via the WIC bus (Weld-Interface-Controller) directly to the welding controller, where they undergo further processing. Scaling data, counters, and mechanical data are also stored within the MGD module. When utilizing the integrated servo function, no additional PLC or machine-side motion logic is required to control the electrode. Thanks to the web-based PRI-web user interface, users can operate the PXC7100 simply and intuitively—either via a computer or using mobile devices.

The IoT Connector enables the transmission of process data, allowing it to be subsequently processed as needed and utilized for quality assurance or predictive maintenance tasks. The IoT Connector supports both MQTT and OPC UA protocols.

A complete solution for continuous cmpacting

In collaboration with partner companies, Bosch Rexroth also develops solutions for specialized welding tasks. For instance, Authorized Partner KombiTec offers the KWZ-Splice—a comprehensive package for the continuous compacting of stranded wires—comprising a compacting tool, a Rexroth PXC7100 controller, pneumatic components, and a cooling system. For higher power requirements, the compacting tool can also be combined with other inverter systems from Bosch Rexroth.

The KWZ-Splice features an integrated displacement measurement system that monitors the compacting height. Via the welding current control, shut-off conditions and monitoring methods can be defined, thereby ensuring that compacting dimensions are achieved in a process-reliable and reproducible manner. To this end, Bosch Rexroth has developed a specific "Compacting Mode" that calculates, visualizes, and logs the specific degree of compaction. This degree of compaction provides a clear indication of whether the required quality standards have been met.