Horizontal machining centre can have retrofitted pallets in the field
At the EMO 2016 machine tool exhibition in Milan (5th to 10th October), Averex Automation demonstrated for the first time a new, automatic pallet change (APC) system for its twin-pallet Akari HS-450i horizontal-spindle machining centre. Sole UK and Ireland agent is Whitehouse Machine Tools, which is able to demonstrate the machining cell at its showroom in Kenilworth.
Unusually, the servo driven, six-pallet unit is designed to be retrofitted in less than a day on a user’s factory floor, although it can of course be factory fitted. Despite the higher productivity and extended periods of unmanned machining offered by APC, the user may not have needed or been able to afford it when originally purchasing the machine. Both 400 and 500 mm pallets can be used at the same time, offering flexibility for accommodating oversized parts and fixtures.
In 2012, when the 4-axis HS-450i was launched, a feature of the machine was the ability to retrofit another major option, namely an extension of the tool magazine. It is easy and quick in the field to expand the number of tool pockets from 80 through 120 to 220 tools, allowing the machining facility to grow with a user's business.
The 12-tonne machine’s construction incorporates top quality components such as single-piece FCD600 castings for the spindle and pallets, Tsubaki ballscrews, THK heavy duty roller guideways, a Tsudakoma rotary table, a high torque, temperature-controlled Fanuc spindle motor with BIG Plus 40-taper tool interface, Kosmek tapered cones on the automatic pallet changer which also has high pressure air clean, and Fanuc 31i NANO control.
By coupling these high-end constituents with economical manufacture in Taiwan, Averex is able to produce a very high precision machine at a competitive price. It is built to exacting standards and includes thermal management of the base casting, ballscrew nuts, thrust bearings, Y-axis servo mounting and spindle cartridge. The machine also boasts hand scraped surfaces for mounting the ballscrew bearing blocks and roller bearing slideways.
An air/oil mist system delivers precise, pressurised lubrication to the ballscrews, roller guideways and spindle bearings, reducing thermal growth and allowing cutting accuracies of 2.5 microns and repeatability of 2 microns to be maintained. Circularity and roundness are quoted as 3.6 and 2.1 microns respectively if the machine is installed in a temperature controlled environment.
The HS-450i is also fast, with a 15,000 rpm / 22 kW direct drive spindle and one-second servo-driven tool change, extending to three seconds when probes, special boring bars or heavy tools are being exchanged. Linear acceleration of 1g to 60 m/min cutting feed rate around the 640 x 610 x 680 mm working volume ensure minimal idle times. Maximum workpiece size is 750 mm diameter by one metre high.
Field expandability by retrofitting a 6-station automatic changer for 630 mm square pallets is also an option for the larger Akari HS-630i twin-pallet horizontal machining centre.