
Tool body from the DH series from Gehring with diamond honing stones
With the Deephone series, Gehring has specialized machines for honing large components in its range. The machinable diameter range for these machines is between 37 and 600 mm, in special cases it can be even larger. Typical applications include large hydraulic and pneumatic cylinders, precision tubes in general plant engineering, extruder housings, aircraft landing legs, molds, etc. Gehring has developed new multi-strip honing tools, the DH series, for machining such components on the Deephone machines. In this concept, the tool body sits on a drive shaft, which in turn is adapted to the machine spindle. The length of the drive shaft determines the possible drilling depth. Gehring offers four gradations: 1,500mm, 3,000mm, 6,000mm and 10,000mm. Quick tool changes are possible thanks to the bayonet connection. Depending on the application, honing stones up to a maximum of 300mm are available.
As the drive shafts are connected to the machine spindle using an adapter, the DH tool series has an extremely wide range of applications. “We are happy to support machining companies that have other, perhaps older, machines with the adaptation,” explains Holger Gehrung, Head of Sales Tools and Cutting Materials at Gehring. “The modular concept of our solution leaves many options open.”
More performance through internal cooling
Two features of the DH series are likely to be decisive for many users: The tools, including drive shafts, are optionally available with internal cooling and air measurement. The internal cooling ensures that the coolant is transported precisely to the machining point. This means higher performance and cutting capacity with a higher surface quality. On the one hand, chip removal is supported and, on the other, the chip/oil mixture is flushed out of the bore, so that the risk of scoring due to jammed chips is noticeably reduced. The more effective internal cooling also performs far better than conventional flooding cooling in terms of coolant consumption, saving the user additional costs. Holger Gehrung on the performance gain: “We assume that our new DH series tools are capable of reducing machining times by up to 30%.”
Air measurement is mainly used with conventional honing machines. In the field of pipe honing, this type of quality assurance is rather uncommon. The advantages are obvious: air measurement allows the diameter to be checked during the process. Without air measurement, the machine operator must interrupt the machining process and remove the tool from the deep bore. Under certain circumstances, the bore must be cleaned before measurement. An enormous investment of time.
But that’s not all. Another highlight of the tools is the integrated linear infeed of the honing stones. Compared to the usual rotary infeed via a toothed rack, this solution reduces vibrations. Not only does this make the process quieter, but vibration-reduced machining also benefits workpiece quality, process reliability and tool life.
Flexible cutting fluid loading
Gehring attaches great importance to flexibility when it comes to abrasives. Depending on the application, diamond, CBN or ceramic honing stones are available, all from our own production. “We can look back on many years of experience with all types of cutting tools and, in addition to honing tools, we also equip finishing and grinding tools of all makes and designs,” emphasizes the sales manager. He continues: “We achieve maximum cutting performance and tool life thanks to the extreme hardness of diamond and CBN cutting grains and their bonding and their interaction, which we tailor precisely to the requirements.” Ceramic abrasives are also available to users as cost-effective alternatives, which also achieve high-precision, defined surfaces. These are suitable for machining almost all materials.
Honing tools are precision products of the highest order, and this also applies to the DH series. Gehrung: “Our users receive top quality – Made in Germany.” In other words, they are manufactured to the highest quality standards. This includes, for example, triple-supported support bars to achieve the best values for roundness, straightness and cylinder shape. The tools are also designed to be very robust, so that the customer can expect a long service life.