Press Release
 

SIX-SIDED MACHINING FOR MEDICAL CENTRIFUGE COMPONENTS

February 2005

A German manufacturer is machining all six sides of an aluminium alloy centrifuge cup on a Chiron FZ 15 KS five-axis machining centre.

The cups are used to hold blood samples for separation in a high-speed centrifuge. They are manufactured from a high strength aluminium alloy normally used for aircraft components which can not only resist the stresses experienced in the centrifuge but can also be sterilized in an autoclave. To prevent vibration the centrifuge load has to be perfectly balanced and so manufacturing to the highest possible tolerances is vital. There are two designs of cup – both produced from a common blank.

The Chiron FZ 15 KS machining centre is built around the moving column concept. This means that the standard fixed table can easily be replaced with an integrated 2-axis CNC tilt and rotary table to give five-axis capability. The table can tilt through 200 degrees at 20 m/minute, while the rotary axis mounted on the tilting cradle can rotate at up to 33m/minute.

The FZ 15’s five-axis capability not only reduces the number of clamping and re-clamping operations, but also the number of fixtures and fixture locations. The result is less complexity, fewer defects, almost no operator input, minimal inventory and a consequent improvement in quality, flexibility, lead time and profitability. It has 48 tools in a chain magazine giving a chip-to-chip time of 2.4 seconds and on this application operates at a spindle speed of 12,000 rpm.

The Chiron machine is integrated in a fully automated cell with parts and fixtures handled using a gantry robot, and an automated station to turn the components over. The cell also features automatic fixture and workpiece clamping. The system is fully flexible and can carry out two five-axis machining cycles on either of the cup designs. The output of the cell is between five and eight cups per hour depending on the combination of parts produced.

The gantry robot picks up a batch of first operation fixtures from a storage area in the middle of the cell. The blanks are then loaded onto the fixtures and join a queue for the first machining cycle. This involves five-axis machining on five sides of the outside of the cup.

The parts are then transferred to a buffer area to await the second machining cycle. When every item in the batch has been machined the first operation fixtures are returned to the pallet store and the second operation fixtures loaded. The semi-machined parts are then automatically turned over and loaded onto the second operation fixtures. The inside and top of the cup are then machined – again using five-axes. Finally the parts are labelled using a needle marker and unloaded from the cell.

The system runs unmanned over three shifts, with the only manual intervention being to load parts, change tools or service the machine.

For more information please contact:

Polly Taylor
Chiron UK
Tel: 01926 818 418
E :ptaylor@chironuk.co.uk
www.turning.biz    www.chironuk.co.uk
www.engtechgroup.com

Andy Sandford
Sticklebacks Communications Ltd
Tel: 01737 270 648
Mob: 07971 436 644
E : Andy@sticklebacks.com
www.sticklebacks.com