Spatter-Resistant Weld-Immune Sensors Deliver Exceptional Reliability and Extended Service Life on Automotive Chassis-Welding Lines

Summary

Automated chassis welding in the automotive sector requires synchronized operation of multiple robots, in complete safety and with minimal human intervention. A misaligned assembly results in damage to the workpiece and potentially one or more robots, but position sensors typically suffer from build-up of welding spatter, causing rapid sensor degradation. Contrinex Weld-Immune inductive sensors with a high-performance ceramic coating are especially resistant to weld spatter and provide a robust, low-maintenance sensing solution with a best-in-class service life.

Customer Application

An automated chassis-welding line in the automotive sector, running at full speed, is a spectacular sight – transfer robots move large, complex parts from one assembly station to the next, while multiple welding robots swoop into position and fuse components together with perfect synchronization.

 It’s all done in complete safety and with little or no human intervention, thanks to an array of sensors and safety devices that protect people, equipment and workpieces – effectively, reliably and almost invisibly. Yet, designers often underestimate the task of ensuring that components are correctly located before initiating a welding cycle. Failure to align two or more parts of an assembly will, at a minimum, result in a costly piece of scrap, and, in the worst case, a damaged robot welding head as well.

 Engineers require presence- and position-sensors that perform reliably in the harsh environment with minimal maintenance over extended periods of operation. Build-up of welding spatter is a common problem, often causing rapid sensor degradation and early failure. In extreme cases, inadequately protected sensors are replaced on a daily basis as a precautionary measure – an unwanted, costly and time-consuming activity.

Customer solution

 For situations where sensors are directly exposed to weld spatter and to strong electromagnetic fields, OEM system integrators specify Contrinex Series 700 Weld-Immune inductive sensors. These rugged devices with one-piece V2A (AISI 303) stainless-steel bodies feature  ACTIVSTONE® , a high-performance ceramic coating that is especially resistant to weld spatter. All external surfaces of the sensor, including fixing nuts and mounting brackets, are protected, preventing spatter accumulation, while optional spatter-resistant shrouding prevents cable damage.

All Contrinex Weld-Immune sensors combine optimum detection sensitivity with immunity to electromagnetic interference, in particular from medium-frequency weld fields (currents up to 15 kA). Robust metal-bodied construction also ensures excellent resistance to the mechanical shocks and vibration present in the harsh surroundings of an automotive assembly plant. Additionally, ACTIVSTONE® withstands frequent and aggressive cleaning regimes, extending the service life of the sensor. 

The specified sensors feature IO-Link connectivity, providing a single, industry-standard interface to the machine control system. During initial calibration, each sensor’s configuration is stored automatically on the local IO-Link Master; this allows plug-and-play replacement of sensors should the need arise, without any loss of functionality and without any need for recalibration.

With sensing distances up to 16 mm and a range of housing sizes, the Weld-Immune family offers solutions for even the toughest weld-related sensing problems. Mounted immediately adjacent to the parts to be welded, these highly reliable sensors meet designers’ needs for a robust, low-maintenance solution with a best-in-class service life in exceptionally tough conditions.

Customer benefits:

  • Rugged inductive sensors ensure accurate positioning of assemblies and components, eliminating welding rejects and equipment damage
  • High-performance ACTIVSTONE® ceramic coating prevents spatter accumulation and inhibits sensor-performance degradation
  • Extended service life as ACTIVSTONE® withstands frequent and aggressive cleaning regimes
  • Weld-Immune sensors provide immunity to electromagnetic interference, in particular from medium-frequency weld fields
  • Industry-standard IO-Link connectivity provides a single interface to the machine control system
  • IO-Link configuration back-up allows plug-and-play replacement of sensors without any need for recalibration
  • Proven technology ensures highly reliable operation with extended service life and minimum down-time

Specific product advantages

  • Rugged inductive position sensors with one-piece V2A (AISI 303) stainless-steel bodies and ACTIVSTONE® ceramic coating
  • All external sensor surfaces, including fixing nuts and mounting brackets, are protected against spatter accumulation
  • Optional spatter-resistant shrouding prevents cable damage
  • Weld-Immune sensors combine optimum detection sensitivity with immunity to electromagnetic interference from welding processes
  • Industry-standard IO-Link connectivity available on all Contrinex sensor product families at no extra cost
  • Diverse portfolio offers exceptional range of sizes plus sensing distances up to 16 mm
  • Reliable, compact vibration- and shock-resistant sensors
  • Industry-standard -25°C to +70°C operating range
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