Currently the five NBH 170 horizontal machining centers with gantry automation for automatically loading and unloading machines are being set up and put into operation in India. Three of these machining centers are equipped with clamping fixtures for rough machining, and the other two are for finish-machining of axle arms. Hüller Hille was able to obtain this order by outdoing well-known competitors from Japan and Germany. Crucial factors leading to the placement of this order were special performance features of the NBH 170 machining center, an innovative manufacturing process with low costs per piece as well as first-class references from European commercial vehicle manufacturers and their subcontractors.
Annual production of 120,000 workpieces in 3-shift operation In the final stage of extension, the system can produce approx. 120,000 axle arms per year in 3-shift operation. Besides drilling and milling with Hüller Hille centers, the process operations of turning, induction hardening, grinding and axial drilling on a vertical center - which are not included in the delivery made by Hüller Hille - are also integrated into the system. As the workpiece is a safety- relevant part, the material is checked for cracks at the end of the manufacturing process. The requirements related to accuracy and the workpiece tolerances significantly exceed general standards. For this, it was necessary to develop a suitable clamping concept, which was implemented in cooperation with Röhm - an experienced partner who is also well- established in India. Rough-machining, i.e. milling, drilling, threading, countersinking and reaming (operation 10), is performed on the blank with a production time/piece of approx. 6.0 minutes. Turning of the spigot, which is otherwise performed at the beginning of the machining process, is carried out in operation 20. A straddle cutter with a diameter of 315 mm is used for rough machining of the inner surfaces of the jaws. The main spindle with a bearing diameter of 120 mm is perfect for this machining operation as well as for plain cutting. This sturdy and precise work spindle has sufficient resources to provide the required accuracy and surface quality. After the intermediate operations of turning, induction hardening and grinding of the spigot, in operation 60 finish machining is performed on two NBH centers with a production time per piece of approx. 6.8 minutes.
The strengths of the NBH 170 machining center clearly lie in its high cutting performance (46 kW/ 1,130 Nm) and availability. The modular core components have proven their worth over years of use in production, and their design was continuously adapted to the requirements of modern production. With a rapid feed rate of 60 m/min, acceleration of 6 m/s², pallet change time of approx. 12 seconds and chip-to-chip time of approx. 5.5 seconds, the NBH 170 center does not need to shy away from a comparison of its technical data to that of its competitors. All NBH centers are equipped with a gantry automation system manufactured by Güdel for automatic loading and unloading of workpieces. Quick loading/unloading cycles are ensured by a dual gripper which can load both workpieces in the clamping fixture. Workpiece buffers in front of each machining station increase the productivity of the system.
Background MAG Industrial Automation Systems, which was founded in 2005, is now positioned within the leading global machine tool builders. With 4300 employees it achieved a turnover of circa 1,5 billion USD during 2006. MAG consists of four groups:
MAG Powertrain (Cross Hüller, Ex-Cell-O and Lamb) supplies agile manufacturing systems and transfer lines mainly to the automotive industry.
MAG Advanced Technologies (MAG Cincinnati Automation, MAG Cincinnati Machine, MAG Fadal, MAG Giddings & Lewis, and MAG Hüller Hille) develops solutions for high performance cutting, automation and composite systems for the aerospace and power generation industries. In addition, MAG Advanced Technologies delivers heavy duty vertical turning centers and machining centers.
MAG Special Machines (MAG Boehringer, MAG Hessapp, MAG +FMS+, MAG Witzig & Frank and MAG Turmatic Systems) manufactures horizontal and vertical turning machines, crankshaft machines, multi station manu- facturing systems and multiway rotary transfer machines for highly precise, high performance applications.
MAG Maintenance Technologies is a unique worldwide service/support organization that helps extend equipment life and maximize return on capital investment.
From forging to finished part.
Hüller Hille NBH centers are being put into operation in India and are now waiting for gantry automation.
Clamping fixture for taking up two workpieces for finish machining.
Rough machining (operation 10) of the inner surfaces of the jaws with a straddle cutter.
Finish machining (operation 60) of the bolt bore hole.
