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Standard components for monitoring safe position

06 March 2018

Leuze is no stranger to the fact that machine safety is an integral part of machine design, as shown with its BPS30 and BPS300 series of barcode positioning systems and new Smart Process Gating (SPG), through which muting processes are made more economical, simple and safe

Machine safety is an integral part of machine design. The use of standard components (sensors, drive elements and control electronics) in safety applications is possible in accordance with EN ISO 13849. This also applies even if these components are not designated as safety components in accordance with Appendix V of Machinery Directive 2006/42/EC. If such components contain embedded software, further consideration must be given to DIN EN ISO 13849-1:2016-06.

To achieve Performance Level c or d with standard components, two channels must be used. Furthermore, the components in both of these channels must provide redundancy based on different ("diverse") technologies. The probability of a common cause failure (CCF) - such as soiling, electromagnetic influences or pressure - is thus virtually completely excluded.

With the BPS30 and BPS300 series of barcode positioning systems in, Leuze provides the required diversity by showing that the software and hardware of the BPS 3xxi and BPS 3x positioning systems have different hardware and software design. This has been verified by the TÜV as an independent body.

In areas in which man-machine collaboration takes place, the requirements of the Machinery Directive with respect to safety-related aspects must be taken into account. In many applications, both a position must be safely detected and a safe speed value set and calculated.

Muting reinvented

Smart Process Gating (SPG) is a new process from Leuze through which muting processes are made more economical, simple and safe. With SPG, the first muting signal comes from the process control (PLC), while the second muting signal is generated by the protective field itself. Smart Process Gating requires a detailed knowledge of the process so that the necessary SPS control signals are made available in the expected time window.

As a result of SPG, signal-emitting sensors are no longer needed

Previously, muting processes with muting sensors were required in order to clearly identify when transported goods are approaching a protective field and to bridge the passing of these goods through the protective field at the correct moment. As a result of SPG, signal-emitting sensors are no longer needed. Synchronisation beams do not have to be taken into consideration. Often, in the case of typical intralogistics applications, the height of the protective device was entirely dependent on the safety-related requirements.

Now, conveyor systems can thus be made more compact. The risk of misalignment or damage to the sensors is eliminated as is the costs for their maintenance and servicing. Furthermore, the purchasing costs, the wiring and risk of manipulation are reduced which increases the availability of the complete safety device.

Bending machine

Bühler Bedachungen und Bauspenglerei specialises in roofing and architectural sheet metal. Jorns AG, a Swiss manufacturer of bending machines, supplied a new double bending machine, the model TP-150G-RH-UV-SL-1250-CP200-6.4-mp, including safety protection for the sheet metal area. Jorns used the RSL 430 safety laser scanner from Leuze electronic, which optoelectronically safeguards access to the long, front side of the machine. The RSL 430 is centrally positioned under the bending basin, ensuring that the maximum radial range of the sensor can be used. The area in front of the machine can thereby be safeguarded with just one sensor.

Only when loading and removing the metal sheets does the machine need to be handled manually. As soon as the machine operator crosses the red line on the floor located approximately 80cm from the bending machine, thereby entering the danger zone of the machine, his movement is detected by the RSL 430 safety laser scanner and the machine comes to an immediate standstill. Should this safety monitor fail, there is a "safety net" in the form of a step bar. If this bar is actuated by the operator´s foot, it presses against an EMERGENCY-OFF command switch that brings the machine to a standstill in a fraction of a second.

Key Points

  • In areas of man-machine collaboration, safety-related aspects of the Machinery Directive must be taken into account
  • Smart Process Gating (SPG) is a new process from Leuze through which muting processes are made more economical, simple and safe
  • The RSL 430 safety laser scanner from Leuze  optoelectronically safeguards access to the long, front side of bending machine

 
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