New SCK synchro-chuck: 100 percent sealed – 100 percent secure
Following a successful series of tests, VW is now using the new SCK generation of synchro-chucks from LMT alliance partner Bilz.
The VW factory at Salzgitter makes about 1.2 million engines each year. The processing and production stages involved are continuously under examination, as it is efficient procedures and top component quality that lay the foundations for a sustained competitive advantage. In Salzgitter there was an acute need for an improvement in the area of clamping devices for thread fabrication suitable for minimal quantity lubrication and for dry machining. Because the clamping chucks that were previously in use were not optimally sealed, as a result of which aerosol regularly escaped, VW turned to the experts at LMT and their alliance partner Bilz, specialists in clamping systems.
Both for reasons of efficiency and for the sake of the environment, Volkswagen uses minimal quantity lubrication and dry machining for more than 50 percent of its manufacturing at Salzgitter. In order to increase this proportion, the company is converting more and more processes to these more efficient methods. In close cooperation with VW Salzgitter, the specialists at LMT and LMT alliance partner Bilz developed a new solution in the SCK synchro-chuck, optimized for MQL machining.
Technical Partnership as the Guarantee of Success
Customized tool solutions, developed in close cooperation with the customer, are the trademark of the LMT partners. The effective and constructive cooperation between VW Salzgitter and LMT's network of specialists proved its value once again with this project - from problem analysis, through the development of a suitable solution up to successful test runs at VW.
- l. to r.: Andreas Heuer, Manager Focus Customer Development at LMT, Jürgen Binnebesel, Tool Engineer in VW's Tool Management Department, and Uwe Leister, Product Manager at Bilz.
"Shared analysis of the process allowed us to localize the existing problems. The solution was to use the synchro-chucks from our alliance partner Bilz, which have been optimized for MQL machining", explained Andreas Heuer, Manager of Focus Customer Development at LMT. "Through using the SCK, the process ensures that 100 percent of the aerosol is immediately carried to the relevant machining locations of the tool. The new design of the Bilz tool holder ensures that oil cannot accumulate in the holder. Any accumulated oil would be forced onto the blade in an uncontrolled way by the air pressure, resulting in the destruction of the blade as a result of thermal shock. Our system prevents that", explains Heuer. The benefits of controlling the aerosol optimally all the way to the tip of the tool are therefore clear: longer service lives, lower parts costs (CPU) and increased machine productivity resulting from less frequent tool changes.
Convincing test series
The ideal sealing provided by the SCK was impressively confirmed in test runs at VW Salzgitter. Clamped into a double-spindle machining centre, the optimized SCK worked in parallel with a clamping chuck of the old type to provide a direct comparison. Using a thread former from LMT Fette, components of AlSi9 were machined using 6 bar MQL pressure and maximum cutting speeds. Jürgen Binnebesel, tool engineer in the tool management department at VW Salzgitter, described the trial, saying that "You could see the difference even with the naked eye; while a mist of very fine aerosol droplets forms around the old chuck, the optimized SCK runs impeccably. No mist, no disappearing into the holder. 100 percent of the aerosol arrives where it should, at the tool." The optimum seal provided by the SCK is at present unique on the market.
Process optimization through innovative synchro-chuck
But the new sealing elements are not the only feature. The SCK is also a big technical step forwards in terms of handling, design and the spectrum of possible applications. As a universally applicable chuck, the SCK replaces several previously separate implementations. Uwe Leister, Product Manager at Bilz, explains this technical innovation as follows: "As a combined solution, the SCK is generally suitable for machines with single or double channel MQL with internal cooling pressure up to 50 bar, and can also be used without any problems for dry machining. It can be used on machines with manual tool exchange as well. Synchro-chucks with sizes HSK 32A, HSK40A, HSK50A, HSK63A and HSK80A are available immediately, along with the coolant transfer sets needed for the different systems. In response to something the customer particularly wanted, the SCK can be delivered with a green ring as an alternative to the blue design, marking the chuck unmistakably as a tool suitable for MQL machining."
The two-sided longitudinal adjustment facility integrated into the collet is also new. Independently of the collet chuck, adjustment can in future be made both through the collet chuck or, quickly and conveniently, through the tool holder.
Practically speaking, therefore, the adjustment can be made directly; time-consuming readjustment is unnecessary. The optimized construction ensures a reliable process, even when stressed by high idling speeds of up to 15,000 min-1. Rigidly mounted individual parts and robust, almost wear-free elastomers ensure that the compact design provides constantly high-quality cutting together with significantly improved service lives, while offering enormous simplification to the assembly work needed before each use.
In addition to the SCK, the product presentation given to the team of experts led by Hans-Otto Wenhake, operative tool manager at VW Salzgitter, drew the attention of the VW experts to another Bilz product: the BZ collet chuck with integrated length adjustment. The great advantages of the BZ design lie in its narrow form, optimum for tight working conditions and awkward contours, as well as in the interlock between the BZ collet and the housing of the SCK. As a result, it is not possible for the collet chuck to race during machining. In addition, the BZ collet makes an important contribution to the 100-percent sealing of the SCK, and is therefore the perfect addition to the chuck. "The project we have implemented at Salzgitter is a good example of what we expect from a tool supplier", adds Hans-Otto Wenhake. "We need the best technical and economical solutions for our production plant, and are always looking for solutions with which our processes can be optimized."