Feed-Out System Makes Machining Center Turning More Efficient

Sept. 30, 2010
Heller system uses additional axis to perform radial-feed movement of the tool cutting edge

Heller’s single-source feed-out system has a drive incorporated in the machining unit, with an adjusting shaft integrated into spindle, and U axis incorporated in the control.

Machining centers are versatile metal cutting systems but using add-on equipment to gain turning capability falls short of true integration, with less than perfect process dependability. Recently, Heller Machine Tools developed a technically and economically viable feed-out system that uses an additional axis to provide radial feed movement of the tool cutting edge. Compared to conventional solutions, Heller indicates, this new feed-out system reduces machining and idle times and much better process dependability.

Aside from being an open system, Heller’s new design has further advantages over other add-on solutions: instead of requiring an individual drive for each facing head, Heller’s solution uses just one drive incorporated in the machine. As a result, the cost benefit increases with the number of facing heads used.

Replaces conventional add-on systems
In contrast to any other feed-out system concept, Heller’s system is a package solution that includes a drive, a connecting link (the adjusting shaft) and a facing head onto which any type of cutting tool can be mounted.

Users of machining centers without turning capability have had no other choice: the workpiece needed to be unclamped for further machining on a turning machine. Until now, there were only a few integrated solutions for use on a machining center. The first is a conventional mechanical head coupled to the spindle and a separate drive unit located adjacent to the spindle within the work envelope. Power is transmitted from the drive unit to the tool via an external coupling.

The second type is a mechatronic system where the drive and facing head form an integral unit. Energy and data are transmitted across an air gap by means of an induction loop.

In Heller’s feed-out system package, the drive unit is coupled to the facing head by means of an adjusting shaft built into the spindle. The facing head carrying the cutting tools is controlled via the U axis — a fully functional machine axis that is programmed through the control. The rotational direction of the adjusting shaft determines the control direction of the U axis, i.e. the direction of movement of the tool (larger or smaller diameter).

Benefits to the Heller approach
As a result of Heller system’s integrated design there is no collision path inside the work area, and since the tools are not equipped with a separate drive their weight is considerably reduced.

An advantage of Heller’s feed-out system over mechatronic solutions is that it has a significantly shorter design, resulting in a reduced tilting moment. Together with the reduced tool weight this has a positive effect on cutting performance and handling.

Another benefit is that when a facing head is placed into the spindle, the adjusting shaft integrated into the machining unit is directly coupled to the facing head. There are no uncovered interfaces. On conventional solutions these would be exposed to coolant and chips and could cause failures.

And, because of the fixed connection between the head and the drive through adjusting shaft, the facing head is always placed into the spindle and removed in a known position; the position of the cutting edge is predetermined. Therefore, the facing head is always ready for immediate use without a time-wasting tryout run.

Reduces valve maker’s cycle time by 50%
To be successful in global competition, companies need to continuously increase their productivity – regardless of the industry they operate in. That is just one reason why pump and valve manufacturer KSB AG, Frankenthal, Germany, opted for a Heller solution for proudcing valve housings. The company uses a single Heller MCH280 horizontal machining center with feed-out system for the production of approximately 40,000 complex bodies/year. This has resulted in a 50-percent reduction in net machining time and a significant increase in process dependability.

The new machining strategy enables the company to perform two different machining processes on the same machine without any problem. This process includes facing of the sealing flanges and machining of a defined turned groove in cast gray iron and ferrocast components. The tools used previously include a multi-edge milling cutter with 12 cutting inserts and an additional cutting tool. With Heller’s feed-out system, machining of the plane surface can be performed in a single step.

From this example it is clear in which cases Heller’s feed-out system is particularly useful. The general rule is: whenever a workpiece requires multiple machining operations allowing full exploitation of the advantages of the feed-out system. The feed-out system is often an ideal solution for the machining of undercuts or internal and external contours.

And the technology guarantees economic efficiency and flexibility: Heller machines with feed-out system allow integration of any given number of facing heads from different suppliers. Another aspect of the Heller feed-out system that will please users is that it is available from a single source, regardless which tool supplier is chosen.

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