PILZ says increasing automation means the demands on machine safety are also rising.
Safety guards or gates ensure that operating personnel are protected against flying metal swarf or hazardous movements on plant and machinery. Other safety considerations include noise, dust and hygiene.
Safety switches maintain the position of these guards and gates. The first step is to carry out and document a hazard analysis and risk assessment for the equipment.
In determining the right solutions for secure safety gate monitoring, aspects of process safety, availability and cost-effectiveness must all be reconciled.
To give operating personnel as much freedom as possible, lift gates and rolling shutter-like constructions have become increasingly popular alongside the classic swing gates or sliding gates.
The challenge is to harmonise safety, productivity and user friendliness on the plant or machine. Productivity is the first priority. However, neglecting user-friendliness can result in personnel tampering with the safety equipment.
Today, non-contact safety switches are increasingly used to protect safety gates, rather than mechanical safety gate switches or roller switches. Non-contact solutions require less work for precision adjustment and have higher service life.
Non-contact safety switches with transponder technology (RFID) are a recent trend, but have established a foothold in the market. These combine the benefits of non-contact safety switches with programmability thanks to individual actuator coding.
When used with machine tools and machining centres with cutting functions, coded safety switches such as Pilz’s PSENcode have the advantage of not attracting metal swarf, unlike non-contact magnetic safety switches.
Guard locking devices are used to prevent safety gates from being opened, so as to protect operators from dangerous overrun movements. However, traditional safe guard locking devices require quite a bit of mechanical adjustment, and have short service lives.
Relatively new to the market are process guard locking devices with integrated, safe position monitoring based on a magnetic action principle. They combine secure safety gate monitoring with a non-contact magnetic interlock in one unit.