Posted to News on 25th Jun 2007, 18:14
'Safety on Board' drives enhance operator safety
Manufacturers of high-output printing and paper converting machines stand to benefit from using Rexroth's IndraDrive with 'Safety on Board' to enhance operator safety, improve process reliability and cut costs. Boasting integrated safety functions, this new generation of drives is certified to EN 954-1 Category 3 and offers extremely short response times of 2ms. These drives can therefore be installed in Rexroth's SYNAX 200 to deliver an integrated safety system.
With printing and paper converting machinery, there are plenty of situations during operation when the machine operator has to work directly on the machine. This is necessary, for example, when changing plates, blankets or tools, cleaning cylinders, webbing up or removing a paper jam or punching scrap. To avoid the risk of accidents in these situations, the EN 1010-1 to EN 1010-5 standards lay down guidelines and safety requirements for the design and construction of printing and paper converting machines.
These requirements are traditionally satisfied through the use of additional monitoring devices and speed sensors. They work in parallel with the controlled drives and cut off power to the drive in the event of a hazard. Rexroth says that, given the constant rise in machine speeds, signal and switching delays mean that these technologies are less and less able to guarantee the required level of personal safety.
Improved machine uptime
With a response time of 2ms, the 'Safety on Board' drive offers decentralised safety at the location of the incident without the need for additional hardware or routing through the control, even with high-speed axes. In addition to improved protection for operators, the safety technology increases the availability of machines, since production can be restarted more quickly after manual intervention than was previously the case.
Rexroth combines the guaranteed single-fault safety with a distinctive package of safety functions. Alongside the Safe standstill and Safe operational stop functions with stop categories 0, 1 and 2, it is now also possible to monitor 'safe movements' at reduced speed, limited increment, limited maximum rotational speed or defined direction of rotation in the drive itself. The safety features are complemented by safe absolute position ranges as well as safe control of a door locking device as soon as all axes of a safety zone are in a safe state. Because power and functionality in the IndraDrive generation have been decoupled, 'Safety on Board' is available in a power range up to 160kW.
