Large, five-axis machining centre can be automated

Citation

(2009), "Large, five-axis machining centre can be automated", Aircraft Engineering and Aerospace Technology, Vol. 81 No. 4. https://doi.org/10.1108/aeat.2009.12781dab.002

Large, five-axis machining centre can be automated

Article Type: Aerospace technology From: Aircraft Engineering and Aerospace Technology: An International Journal, Volume 81, Issue 4

Following Hermle’s introduction of the C 50 U vertical machining centre for three- to five-axis machining of workpieces weighing up to two tonnes, the German manufacturer has announced the availability of a pallet changer and other automation equipment. UK agent, Geo Kingsbury Machine Tools, says that the new options can be retrofitted to machines already in service.

At its simplest level, the rotary twin pallet changer, PW 2000, allows off-line setting of the next workpiece to maximise spindle up-time. At their most complex, the automation options include storage for up to 21 pallets and their transport to and from the spindle(s) to create a flexible manufacturing system involving one or more C 50 Us.

In addition, external magazines offer an extra 41 or 162 pockets for SK 40/HSK A 63 tools or an additional 124 tool pockets for the SK 50/HSK A 100 interface. These tool storage systems supplement the machine’s internal magazine, which holds 60 of the former size tools or 42 of the latter. A control panel running its own tool management program is located directly by the cutter loading position for direct input of tool data (Figure 2).

Figure 2 A Hermle five-axis machining centre, C 50 UP, which is its designation when fitted with a PW 2000 pallet changer at the front. The schematic also shows the addition of a 124-position tool magazine (right) for SK 50/HSK A 100 tools

The add-on tool magazines increase production output by minimising machine stoppage for changing worn cutters or adding new ones. They also allow long periods of lights-out machining. To extend the automation possibilities further, there are robotic options for loading and unloading components on and off the pallets.

The PW 2000 was designed specifically for the C 50 U and is able to handle up to 2,000 kg/side, including the weight of the component, fixture and pallet, which is either 800 × 800/Ø 1,000 mm or 1,000 × 800/Ø 1,166 mm (Figure 3).

The system consists of a numerically controlled unit travelling in the Y-axis, equipped with a lifting device and a rotary element with double gripper to effect pallet exchange into and out of the machining area. Large access doors at both the front and the side allow the machine operator convenient access when proving out jobs.

Figure 3 The PW 2000 automatic pallet changing system for the C 50 UP five-axis vertical machining centre

Most Hermle C-Series machining centres are configured as five-axis machines with an integral, +30/−115° swivelling trunnion supporting a rotary table. Despite its large size, with a working envelope two and a half times bigger than that of the next largest model in the Hermle range, the C 50 U is capable of single-digit micron accuracy.

Production potential is high owing to 6 m/s² acceleration to traverse rates of 60 m/min in the X- and Y-axes, 55 m/min in Z. Specification of the SK 40/HSK A 63 spindle is 18,000 rpm/39 kW, while there are two 60 kW versions for the larger tapers – 9,000 rpm for SK 50 and 12,000 rpm for HSK A 100. Components can be machined within a 1,000 × 1,100 × 700 mm volume.

Control options are Heidenhain iTNC 530 or Siemens Sinumeric 840 D, both enabled for the latest Cube 67/Profibus digital communication and networking.

Details available from: Geo Kingsbury Machine Tools; Tel.: +44 (0) 23 9258 0371; Fax: +44 (0) 23 9250 1741.