Mitsui Seiki 5-axis enhancement slashes changeover times

When compared to any other 5-axis machine tool/control combination, ADFO overcomes the general problem where the orbiting points of the rotary axes have to be taken into account to achieve or maintain accuracy of form and surface finish. In normal machining, this is a direct reflection on the quality of fixturing, datum alignment and geometric relationship of the part to the programmed centre points. This means that all too often time-consuming delays occur as the part program has to be reposted in order to offset any setting error that involves subsequent parts. It can also demand more elaborate and hence costly fixtures or the operator to be relied upon to always remember to set new parts back to their respective centre positions. With the new software routines, the Mitsui Seiki operation can simply apply a work co-ordinate offset adjustment and the Fanuc 31i control will continuously track and, in real time, dynamically update the part program vector points. Indeed, in certain applications a spindle probe can be used to determine the part datum from which the control will automatically apply the 5-axis work co-ordinate offsets. Further enhancements to the machine include the expansion of the working volume by almost 30%, an increase in rapid traverse rates by a massive 60% to 32 m/min and a pallet change time shortened by more than half. In addition, in its latest guise, the HU63A is able to maintain 0.001 mm accuracy over its extended working volume of 900 mm in X and 800 mm in Y and Z axes. To help productivity gains, it is able to rapid traverse in three linear axes at 32 m/min. A choice of spindles is available to make the machine application-specific, with a 50 taper, 18.5 kW general machining version developing some 500 Nm of torque and 15-6,000 rpm. A 30 kW, 50 taper, 120-12,000 rpm spindle is available for heavier cutting on materials as diverse as aluminium to hardened steels, and a 15 kW, 200-20,000 rpm, 40 taper version is available to provide high speed cutting cycles. A feature of the HU63A 5-axis horizontal machining centre is Mitsui Seiki's patented tool clamp mechanism for the spindle taper incorporates a force multiplying mechanism that achieves a pull-back force of 500 kg. To release the taper, the Mitsui Seiki design requires just 20 to 25% of the normal release force demanded by more traditional systems ,thus significantly reducing stress on the spindle bearings. Toolchange time is just 2 secs for tools up to 380 mm diameter (adjacent pot empty) by 450 mm long and a range of tool magazines are available to hold up to 180 tools. The pallet systems available can accommodate up to 10 pallets each 630 mm by 630 mm. There is a range of options for automated machining operation including probing, tool life control, tool length and broken tool sensing, as well as adaptive control and scheduling up to full cell and system engineering.