Compensating 6-point clamping lowers manufacturing costs
When maintaining high precision and tight tolerances, traditional three-jaw chucks quickly reach their limits. Manufacturers that reach that point and wish to increase their capabilities must choose a path forward. With INOZet®, Neunkirchener Achsenfabrik AG discovered a solution that is cost effective, time saving and easy to implement.
Located in the German town of Neunkirchen am Brand, Neunkirchener Achsenfabrik AG (NAF AG) is an international leader in the production of axles, transmission gears and tandem axles. Founded in 1960, the family-run company is currently in the hands of is 3rd generation of owners.
NAF AG attributes its success to holding itself to demanding quality standards and a commitment to constant improvement. Its products can be found driving machines for construction, forestry and agriculture around the world.
“The primary factors for smooth running, service life and reliability, for instance, of our transmission gears and axles involve a high degree of accuracy and precision,” says Klaus Bungeroth, Head of Manufacturing Development at NAF AG.
The definitions of accuracy and precision have consistently risen over the years, as customer requirements for cylindricity and concentricity have increased. While H8 components used to be acceptable, today H7 or H6 are the norm.
“When we still manufactured the parts in the traditional three-jaw chuck, an immense measurement outlay was needed as it was exceptionally difficult to reach the tolerances required,” says Mr. Bungeroth. “The inspections meant that we lost a huge amount of time.”
In its constant pursuit of process improvement, NAF AG became aware of the INOZet® clamping system, which converts a 3-jaw chuck into a compensating 6-jaw chuck in mere minutes. The company benefited from the compensating effect, which offset out-of-roundness in the blank and resulted in the clamp reliably achieving consistent contact with six points on the component. Moreover, doubling the points of contact more evenly distributed gripping forces to minimize polygonal deformation.
The combination of the compensating effect and increased number of jaws resulted in NAF AG being able to hold higher concentricity requirements more easily and reliably. The company found it was able to convert chucks with INOZet® in less than ten minutes, and that one set of gripping jaws could be used to cover the full clamping range of the chuck for both inner and outer clamping. As NAF AG first began to integrate INOZet®, it quickly became apparent that the system reduced part deformation to such a degree that it eliminated a secondary operation.
“It was immediately clear to me that fitting this clamping system would considerably improve the concentricity,” says Mr. Bungeroth. “As we can decisively lengthen or extend the inspection interval, we now have less work and thus lower costs.”
NAF AG quickly acquired and implemented INOZet® pendulum bridges for 250 mm, 315 mm, 400 mm, 500 mm and 630 mm chuck diameters. Compared to the alternative of purchasing and installing true 6-jaw chucks, the system required far less outlay in terms of both cost and time.
“The considerable flexibility of the INOZet® clamping system enables us to convert a 3-jaw chuck to INOZet® 6-point clamping within a few minutes,” says Udo Schroft, an NAF AG employee. “Concentricity is far less of a topic today; it used to be quite a different story.”