PRODUCT REVIEWS
Dreefs ’ managing director , Harald Müller , in front of the new Bihler BIMERIC servo production and assembly system .
1,100 welds per minute a way that , compared to the usual horizontal time sequence of separate , successive operating steps , the individual process steps follow one another much more rapidly and , in some cases , run in parallel . The welding electrode therefore starts to close while the strip is still moving , taking full advantage of this onset phase . These tuning measures , accomplished to an accuracy of milliseconds , not only brought about the desired increase in speed but also another advantage …
“ The optimised travel profiles also help to reduce wear at the units ,” explained Müller . This is because the feed mechanism no longer needs to work at full speed to be as fast as possible but is instead able to run more slowly , thanks to improved timing .
“ Even at the highest speeds , the BIMERIC runs extremely quietly and stably ,” added Müller .
Increased efficiency
For two years Dreefs Schaltgeräte und -systeme GmbH has been using a Bihler BIMERIC system to manufacture stamped and formed parts with silver contacts . Working with his team , managing director Harald Müller programmed the NC units via the VC 1 controller to enable the system to perform a possibly record-breaking 1,100 welds per minute – and save more than € 100,000 worth of silver each year at the same time .
Dreefs Schaltgeräte und -systeme GmbH was founded in 1903 and has been part of the Italian Everel Group since 1998 . The Group is one of the world ’ s leading suppliers of electromechanical components for domestic electrical appliances , the automotive industry and the healthcare sector .
The portfolio includes oven switches and ceramic cooktop regulators , as well as contacts for car door locks and blower switches . For all these components , for which final assembly is performed in Italy and Romania , Dreefs manufactures the necessary stamped and bent parts – approximately 440 million of them each year . For many years , stamped and bent parts with welded silver contacts , in particular , were manufactured on five older punches and welding systems , of which four were replaced in late 2018 by a Bihler BIMERIC BM 1500 servo production and assembly system .
In-house development work
“ To manufacture the silver contacts , the new BIMERIC BM 1500 performs approximately 550 rotations and produces approximately 1,100 welds per minute – a potentially record-breaking speed that actually considerably exceeds the machine ’ s normal capacity ,” said Bihler .
This performance was enabled by the intensive extension and optimisation work that Dreefs performed in-house on the system .
“ We acquired just the machine body of the BIMERIC , the NC units and the feed mechanism . Everything was only loosely pre-assembled and we developed the strip guide and positioning system for the electrode holders ourselves ,” recounted Dreefs ’ managing director , Harald Müller . “ We then attended the Bihler training course on the VC 1 controller before programming this to meet our exact requirements .”
The clear traceable program structure of the VC 1 controller provided many possibilities for this task . As a result , it was possible to program all the necessary travel profiles and , in particular , all the NC units in such
“ Another vital consideration was the fact that we can continue to use our 300 or so existing tools on the new system .” At present , 80 tool sets are already in use at the BIMERIC . “ We also benefit from the short set-up times , which we have reduced from as much as twelve hours to just four hours today ,” continued Müller .
The BIMERIC machine also reduces the amount of silver required for the contacts each year by at least 20 per cent , saving approximately € 100,000 , because it produces larger weld connections and thus allows smaller-sized silver contacts with no loss of functionality .
At Dreefs , the VC 1 controller data is used for process monitoring and the complete status of each manufacturing job is visible in real-time in the EMS system .
“ This capability dovetails with the Industry 4.0 principle which is consistently and coherently implemented at Dreefs and with which the new BIMERIC machine , with its enhanced capacity utilisation , efficiency and quality , is fully compatible ,” concluded Dreefs .
Parts manufactured at Dreefs .
The profiles and start times of all the units are programmed to run simultaneously , to a certain extent , for high manufacturing speeds .
48 | sheetmetalplus . com | ISMR March 2021