KOMET has developed a new PCD drilling tool for drilling water and freeze plugs, which, thanks to its innovative chip spoilers, prevents chip build-up in components.

Engine blocks generally contain “water plugs” or “freeze plugs”, which – in the event that the coolant freezes – prevent damage to the engine. The KOMET GROUP has a specific range of tools to create the drill holes for these plugs, including a particularly efficient brand new PCD drilling tool equipped with “chip spoilers”, which are highly effective at preventing chip build-up in components. The key to this is  KOMET’s  use of additive manufacturing, which makes it possible to construct highly intricate chip spoilers with optimised, curved cooling channels.

Although the chip space on a conventional drilling tool is open to the side and the front, the chip spoiler on every cutting edge covers the groove frontally and radially. That leaves only a narrow gap of a few tenths of a millimetre between the spoiler and the cutting edge of the tool, through which any chips produced can run off. The spoiler channel then guides them reliably out of the drill hole. That’s how the new water-plug drilling tool can be used to prevent chips remaining in the drill hole. Furthermore, initial experiences in production have shown that the cost of monitoring chips remaining in components has reduced considerably.

KOMET has developed a 6xD indexable insert high-performance drill bit that retains its stability even when working without a centring point or guide rails.

5xD is as good as it gets when it comes to the length/diameter ratio of drilling tools. Or at least, that’s what was previously thought, since larger ratios have a considerable adverse effect on stiffness; until now, stable machining operations and adequate feed rates have been mutually exclusive. But the KOMET GROUP has been hard at work, pooling its many years of experience and sophisticated development methods to come up with a new, 6xD drill bit with performance data that will not fail to impress.

The impetus for the project was provided by a customer who enquired about the possibility of a productive 6xD 33-mm drill bit for making large screw holes for bearing rings of the kind used in wind turbines, for example. Tools of this size normally have guide elements, such as a centring point or guide rails, which makes the manufacturing process significantly more complex and drives costs skywards. In the words of Dr. Michel Maes, Head of Development at the KOMET GROUP, “Although you can find cheap 6xD drilling tools on the market that do not feature guide geometries, these are generally only able to work at relatively low feed rates and are therefore not particularly productive.”

The new KOMET KUB Pentron^® 6xD indexable insert drill bit has been designed to be a low-cost, high-performance alternative without guide elements, which does not compromise on productivity or process reliability – just like the successful KOMET KUB Pentron^® 5xD, which the Besigheim-based drilling specialists used as the gold standard for stiffness in this latest endeavour. Development Engineer Julius Osterried explains, “Our finite element analyses concluded that the stiffness of a 6xD tool was up to 45 per cent less than that of a 5xD tool.” To counteract this, the developers had to make changes to the basic body, since both the substrate from the KOMET KUB Pentron^® and the successful Pentron W80 indexable inserts were to be retained for the new tool design.

Julius Osterried describes the next stage in the development process: “To establish the kinds of loads that would be encountered, machining tests were conducted in which forces were measured, and the results from these were compared with results achieved using simulation tools – both numerical and hybrid.” “We collaborated with other organisations such as universities, who were able to bring the latest scientific expertise to the table.” In a screening, the KOMET developers then established which geometric characteristics have a significant influence on stiffness. Armed with these findings and their experience, they used the design of experiments (DoE) and finite element (FEM) methods to optimise the geometry of the basic body in order to achieve a stiffness that is sufficient to withstand the specific loads to which it is subjected on the lateral force plane. The development team turned promising design variants into prototypes and validated them by means of drilling tests.

The results of this testing were used to create the final design of the new, 6xD drill bit, which was then taken to the customer for field testing. The drill bit needed to prove itself for roughing operations in 42CrMo4 quenched and tempered steel. At feed rates of up to 0.12 mm/rev and cutting speeds of up to 176 m/min, the new, 6xD drill bit has done just that, achieving positive results in terms of the hole diameters it can drill, which are within the tolerance limits set out in the specifications. In addition to this, the anti-penetration cutting forces of the drill bit, chip evacuation and quality of the drilled hole fulfil the customer’s requirements.

Head of Development Dr. Michel Maes concludes, “With this kind of cutting data and the results it has achieved in testing, the new KOMET^®KUB Pentron^® 6xD indexable insert drill bit without additional centring point is set to be a highly productive tool for 42CrMo4V machining. It allows us to achieve tool life travel of up to 9.9 m. Not only are these figures considerably higher than comparable drill bits without guide elements, but they also demonstrate that the new tool can hold its own against its guided counterparts. Ultimately, our customers are very pleased with the outcome.”

The new KOMET KUB Pentron^® 6xD indexable insert drill bit is now already in use in the field, and developers have wasted no time getting to work on additional 6xD drill bits with other diameters.

With the slogan “THE CUTTING EDGE – Solutions for top-quality performance” the KOMET GROUP showcased more than 1000 new products for efficient machining at the EMO Milano 2015. “Achieving a competitive advantage by using cutting-edge technology is the promise we are making to our customers,” is how Dr. Christof Bönsch, Managing Director of the KOMET GROUP, describes the meaning behind this year’s trade fair slogan. “Customer focus and process optimisation are our primary concerns,” Dr. Bönsch goes on to explain, “because increasing performance, productivity and efficiency for our customers is – for us – the principle driving force behind the development of new products.”

Complete product portfolio In addition to the familiar tool portfolio for high-precision drilling, reaming and threading, the KOMET GROUP in particular, be presented at the EMO 2015 an extensive new range of high-performance milling cutters, thereby emphasising once again its leading position in the area of technology and innovation. In addition to the already successful KOMET^® Quatron hi.feed, KOMET^® hi.aeQ and KOMET^® hi.apQ range of milling cutters, six further indexable insert milling cutter systems are now also included in their ex-stock range. KOMET has also extended its leading position in bore machining as a result of a consistent further development of its product range.

Technology precursor in Industry 4.0 With the ToolScope system, the subsidiary KOMET^® BRINKHAUS provides an efficient, high-end technology in the area of machine and process monitoring. With the new firmware version 10 and its user-friendly applications, the assistance system for machining production now marks a milestone in Industry 4.0.

Investment in innovation

Management at KOMET is extremely pleased with the business transactions and growth in turnover achieved in the current year. Dynamic growth is particularly evident at the European subsidiaries. “Growth in the first half of the year was above 10%,” says Matthias Heinz, Managing Director of the KOMET GROUP, “and we expect to see a continuation of this extremely positive trend for the second half of the year.” The focus of investments, which are being maintained at a continuously high level, is centred on the area of innovation. “We invest around 8% of turnover in development,” Heinz goes on to explain. In the current business year, our main interest has been primarily the expansion of our own carbide production.