PRODUCT REVIEWS
Conductive brazing of contacts
“ Using optimised Bihler process technology , it is now possible to apply 10 x 10mm contacts to copper carrier strips of up to 5mm in thickness . They are attached using conductive resistance brazing with precision-controlled energy input to achieve components with very high dimensional stability on strip or finished individual parts ,” Bihler told ISMR .
Welding and , in particular , resistance welding has been one of Bihler ’ s core competences for decades . One important application in this field is contact welding i . e . the application of small preciousmetal round wire , lamellar or profiled-strip contacts to strip material .
“ In this area , we have implemented thousands of welding applications that guarantee process reliability , productivity and weld quality . In contact welding , we recently witnessed an increase in demand for load break switches . The contacts of these components ensure that electricity supply is disconnected quickly and reliably , should the need arise . They are installed , for example , in electric vehicles and as load switches in domestic engineering applications ,” explained Bihler .
“ Because these components are exposed to particularly high amperages , they need to be sufficiently large for the contacts to be attached to the corresponding carrier strips by resistance brazing . In the past , however , process-related considerations meant that the thickness of the carrier strip , which is usually made from copper , was restricted to a maximum of 3mm ,” it continued .
Unlocking production potential
Bihler has now unveiled a new innovation for the resistance brazing of contacts . The existing process has been optimised in a way that enables 10 x 10mm contacts to be applied to copper carrier strips with thicknesses of up to 5mm . This , said Bihler , represents a huge leap forward in resistance brazing technology and “ unlocks a world of production potential .”
While most contacts of this sort are applied using inductive brazing , Bihler uses conductive brazing . This is not only faster but also offers thermal behaviour benefits .
The new large-format resistance brazing process , using the B 20K welding controller , makes it possible to manufacture up to 30 welded parts per minute .
Using the new conductive resistance brazing process , it is possible to apply contacts measuring up to 10 × 10mm to 5mm-thick copper carrier strips .
Conductive brazing only partially heats the component and just introduces a small amount of heat into the area of the contact . This has a very positive effect on the dimensional stability of the component .
“ The vital element in this new largeformat resistance brazing process is the B 20K welding controller , whose performance capabilities have once again been enhanced for this task ( particularly the inverter and transformer ). In practical operation , the components are fed to the welding point and the multilayer section that is to be brazed is drawn in by the welding system and separated . The two components are positioned under the electrodes , which then close and perform the resistance brazing operation . This normally takes one second . The system then opens again and the components are stepped forward in the cycle or are removed from the welding position . In general , it is possible to manufacture up to 30 welded parts per minute in this way ,” highlighted Bihler .
The entire process can be implemented in a stand-alone unit or integrated into neighbouring Bihler systems . These particularly large contacts can also be brazed to strip material or to finished individual parts “ without any significant impact on the prefabricated contours of these parts ,” according to Bihler .
As a leading system supplier for stamping , forming , welding and assembly technology , family-owned Bihler has over 70 years of experience in manufacturing technology that is ‘ Made in Germany ’. It also offers tailor-made automation solutions to the market . n
www . bihler . de
ISMR May 2024 | ismr . net | 69