Precision Resistance Welding Control for Micro Applications

Bosch Rexroth has developed the PXC7100, a cost-optimized control system for resistance welding processes requiring high precision at low current levels. The solution is designed for applications in the metal and electrical industries, including splice compacting of micro strands, sensor contacting, and battery welding, where process stability and repeatability are critical.

Low-current resistance welding for coated conductors
The PXC7100 is specifically engineered for welding tasks involving small components and low current ranges. Unlike ultrasonic welding, resistance welding enables the processing of coated conductors, allowing extension or compaction of strands with protective coatings such as tin. This capability is relevant for electronic applications where corrosion resistance and material integrity must be maintained.

The system supports splice compacting processes, where conductor strands are compressed and joined to achieve defined electrical and mechanical properties.

Simplified commissioning and reduced cabling
The control system is operated via the web-based PRI-web interface, which includes a setup wizard for rapid commissioning. This reduces configuration time and simplifies integration into production environments.

With the optional Measuring Gun Data (MGD) module, all sensor and signal data can be transmitted via a single bus cable. This architecture reduces wiring complexity and installation effort. The MGD module digitizes process and sensor data directly at the welding head, including force, position, current, and transformer parameters.

Data is transmitted in real time to the control unit via the Weld Interface Controller (WIC) bus at a cycle rate of 1 kHz, enabling precise monitoring and control of the welding process. Additional parameters such as scaling values, counters, and mechanical data are stored within the module.

Integrated motion control and intuitive operation
The PXC7100 includes an integrated servo function, eliminating the need for external PLC-based motion control for electrode positioning. This simplifies system architecture and reduces hardware requirements.

Operation is handled through the PRI-web interface, accessible via desktop or mobile devices, allowing flexible interaction with the system in industrial environments.

Data integration for quality assurance and maintenance
Process data can be transferred via an IoT connector supporting MQTT and OPC UA protocols. This enables integration into higher-level systems for data analysis, quality assurance, and predictive maintenance within a connected manufacturing environment.

Integrated solution for splice compacting
In collaboration with partners, Bosch Rexroth also provides application-specific solutions. The KWZ splice system, developed with KombiTec, combines a splice compacting tool with the PXC7100 control system, pneumatic components, and a cooling unit.

The system includes an integrated path measurement function to monitor compaction height. Welding current control allows definition of shutdown criteria and monitoring strategies, ensuring consistent and reproducible compaction results.

A dedicated compacting mode determines, visualizes, and records the compaction level. This parameter serves as a quality indicator, enabling verification of process outcomes against defined production requirements.

Edited by Maria Brueva, Induportals editor – adapted by AI.

www.boschrexroth.com