Manufacturing Technology

One of the main tasks in metal cutting is to extract the enormous heat in the cutting zone efficiently. This is quite a challenge, especially in turning work where there is continuous contact between the cutting edge and the workpiece. ARNO Werkzeuge has therefore developed the ARNO Cooling System® (ACS), which feeds coolant directly to the cut point via two channels from the top and the bottom.

ARNO has developed the ACS system in two variants – ACS1 and ACS2. With the ACS1 variant, the coolant jet is guided along the insert seat in a coolant channel and emerges directly at the cutting zone. The coolant then effectively goes under the chip and optimally flushes it out of the cutting zone. This drastically lowers wear and significantly prolongs the service life of grooving and parting tools.

With the ACS2 variant, the coolant channel at the insert seat is coupled with a second flow optimised coolant jet from the bottom onto the tool flank. The latest developments offer this coolant channel with a triangular outlet, which supplies coolant across the full width of the insert right through to the edge. 

Tool set-up and application is also optimised. Traditionally the optimum coolant supply of an external cooling system is manually positioned and, often, inaccurate in application. The internally guided coolant jet however, always goes precisely where it has the greatest effect – to the cutting zone and the tool flank. It also minimises the risk of material build-up on the cutting edge and the associated crumbling.

ARNO has also utilised the innovation of additive 3D printing methods to produce advanced technology part off modules. For the first time, this method also permits the production of a triangular shaped coolant outlet so that the coolant jet is precisely controlled to off the maximum cooling effect with minimum consumption and to ‘flood’ the furthest edge of the tool flank. These optimised cooling conditions also permit further potential optimisations, such as a reduction in insert width. Specific applications have shown that a part off tool of 1mm less in terms of insert width, with 20 machines and on 220 machine days, means a reduction in annual costs in excess of GB£400,000.

With the ACS2 from ARNO, users feed coolant to places that were previously impossible. As this supply’s coolant under the chip, the chip breaks optimally and is flushed more easily out of the cutting zone. Chips are shorter and the tendency for built up edge insert conditions are greatly reduced. Measurements confirm that this coolant method reduces temperature by about half.

ARNO explains: “As a result, the tool is exposed to much less stress and flank wear is considerably reduced. Instead of having to lower cutting and feed rates to protect the tool, rates can even be increased. Productivity also rises since tool life is significantly longer. Users report that their tools last up to three times longer or at least twice as long. Fewer tool changes ultimately relieves the work burden on operating personnel, not to mention significantly reduced machine down time.”

Users don’t need to go without direct cooling, even in turning operations. With the right tool holder, the integrated channels feed coolant close to the cutting zone. No complex adjustments are needed since the plug-and-play system always fits. Optionally, the manufacturer offers a VDI holding tool to match the tool holders and it feeds coolant to the holder without any pipe or hose connections.

Integrated cooling is even possible on sliding head lathes where tools must be frequently changed. Here, ARNO recommends its AWL sliding heads tooling solution and the AFC
quick-change tooling system. The AWL tool holder system (patent pending) offers bespoke solutions for a wide range of sliding head lathe manufacturers’ machine tools. The AFC quick change tool holders are mounted on a fixed stop and the required insert can be fitted or removed via two quick release clamping screws. Two separate cooling channels in the tool holder system can be opened or closed to permit tools with and without through tool cooling to be used in parallel. 

“It is almost always beneficial to use tools with tool cooling wherever possible and when you also find a tool manufacturer that understands the manufacturing scenarios and has given a lot of thought to the process, productivity receives a real boost,” comments ARNO.