Radical reduction in machining times! The newly developed pick-up turning machine VLC 250 P reduces workpiece changeover times by 83% with the application of its pendulum technique. In fact, the time it takes to change a chucked workpiece is reduced to 1 second. With the VLC 250 P EMAG extend their Machine Platform 250 by another highly productive vertical turning machine for use, primarily, in a medium or large batch production environment.
VLC 250 P – the idle time killer!
06/10/2010 - Oliver Hagenlocher
The developers of the VLC 250 P clearly focused on the reduction of idle times. Those periods during which the machine did not produce – when it was being loaded or unloaded – had to be eliminated. The VLC 250 P proves its particular worth when it comes to workpieces with short machining times, where the ratio between cycle time and idle time is the decisive factor in establishing the efficiency of the machining process. In other words: where workpieces are to be machined at very short cycle times the proportion of idle time weighs particularly heavily against overall efficiency. This is remedied with the VLC 250 P, as the application of its pendulum technique sees idle times reduced to an absolute minimum.
The machine can be used as a stand-alone or in a production line. It performs to greatest advantage when machining workpieces with a cycle time of less than 30 seconds. With these components the idle time is the deciding factor in establishing the overall processing time. On conventional turning machines the workpiece changeover time is approx. 6 seconds. The VLC 250 P needs just 1 second. That equates to a reduction in changeover times of 83%.
The concept also offers advantages in turning the first and second side of the component. Where the workpieces are produced on two machines or on a DUO version, output rates are always determined by the time the slowest operation takes up. Although operations on the VLC 250 P can also be of unequal duration, the cycle time is always the sum of the times taken up by the individual operations.
A dynamic system for minimal idle times
The turret indexing time is just 0.3 seconds – one of the preconditions that ensure the chip-to-chip time for tool changes is as short as possible. The workpiece changeover time is just 1 second. Lower idle times mean high output rates and lower unit production costs. The vertical turning machine VLC 250 P features a slide with two spindles that are moving in unison. While one holds the workpiece during machining, the other unloads a finish-machined component and picks up a new raw-part. In other words, one spindle is always in the machining area, where the component is machined by X-axis turret tools.
The machining process is supported by a main spindle with a power rating of 28 kW and a torque of up to 300 Nm. The turret with VDI 50 tool receptors accommodates 12 turning or up to 12 driven drilling or milling tools. A chuck with 250 mm diameter holds workpieces of up to 200 mm diameter and 80 mm height. The second side of the workpiece is machined with the help of a compact, integral component transfer+turning station.
Energy efficiency is integrated
The running costs for energy consumption can mount up quite quickly. The VLC 250 P has been built with the careful, responsible handling of resources very much in mind. Only components necessary for the efficient, quality- maintaining processing of the workpieces have been retained. The machine base and overhead slide in Mineralit guarantee great stability and efficient vibration damping, which – in turn – leads to an extended tool life. All guideways are located overhead and thus outside the machining area, where they are well protected against the ingress of chips and dirt. This ensures constantly maintained accuracy and process integrity and reduces the maintenance effort. Telescopic covers, so susceptible to failure, are not found on the VLC 250 P.
The advantages offered by the VLC 250 P
- Extremely fast workpiece changeovers
- The VLC 250 P can carry out follow-on operations (turning 1st side + 2nd side) and complete-machine a variety of workpieces
- Reduction in unproductive times
- Optimal accessibility and operator comfort
- Vibration damping and thermal stability through machine bed and compound slide in Mineralit®
- Standardised automation modules ensure great flexibility
- Ideal chip flow conditions – chips fall unhindered to the bottom
- The compact design makes for a small footprint
By the way,
technologically optimised production processes – and consequently cost-efficient machining sequences – form the basis for future-orientated manufacturing systems. They do, however, cover not only the investment in machines and production tools as such, but also – and this is of decisive importance – the operating costs and machine availability.
EMAG uses the same basic components in many of their production line machines. This drastically reduces maintenance, repair and training costs.