Enhanced cycle efficiency

Illustration | design hoch drei GmbH & Co.
Marginal Column

Retooling record: the RV 10 Flexmaster is equipped with a vertical indexing table with ten clamping stations.
Photo: Winema Maschinenbau GmbH

The HNC100® series 3X controls up to four electrohydraulic axes.

The RV 10 Flexmaster achieves a 20 percent greater output.
Photo: Winema Maschinenbau GmbH

March 2012

 

With maximum flexibility, minimum setup times and extremely short non-productive times, rotary indexing machines like the Winema RV 10 Flexmaster are breaking into the domain of cam-controlled machines. Designer Eckhard Neth, Managing Director of Winema Maschinenbau GmbH, discusses the road to maximum output.

 
 

Our customers want maximum output with the shortest possible setup times. This is particularly true for price-sensitive mass products such as plug pins, cam discs and cable connectors made of all types of metal materials. However, ancillary times below 0.3 seconds were only possible up to now using cam-controlled machines, which require compromises in the machining processes and often setup times of one half to two shifts. With the newly developed RV 10 Flexmaster for small workpieces from two to 13 millimeters in diameter, Winema now boosts productivity by 20 percent compared to today’s conventional solutions. Our rotary indexing machine boasts a complete setup time of around 1.5 hours – four to six times faster than comparably equipped cam-controlled machines.

For parts families with an annual volume of five to ten million units, we surpass the speed of cam-controlled alternatives and combine this with the advantages of CNC technology for enhanced flexibility. Up until now, no machine manufacturer has been able to satisfactorily meet these requirements for the entire workpiece spectrum. The highly dynamic processes are made possible by the extremely high rigidity of the load-bearing components and optimizing the masses of the moving parts as well as extremely tight manufacturing tolerances.

54 electrical and hydraulic CNC axes

On account of the compact machine form, only hydraulic drives can be used for linear motions. They enable rapid acceleration and an extremely dynamic control response. This means that the use of wearing parts to transfer force is obsolete. Additionally, the heat produced by the drive can be easily dissipated at the hydraulic station outside the machine tool – significantly reducing thermal stress. From our perspective, Rexroth offers the only complete system on the market that provides control units, hydraulic controllers and control valves from a single source. Consequently, we are using the IndraMotion MTX CNC system solution for the first time in our new RV 10 Flexmaster. It meets all requirements for quality of control and dynamics for a large number of axes. In the MTX performance version, it controls the 54 CNC axes of the RV 10 Flexmaster, 27 of which are IndraDrive spindle drives.

Thanks to its lean architecture, the CNC core can also execute the Flexmaster’s complex tasks in an extremely short time, thus reducing non-productive periods. The highly dynamic torque motor increases output even further. It positions the indexing table so precisely that the hydraulically clamped spur gear can engage immediately. This enables us to reduce unproductive ancillary times to less than 0.3 seconds.

Unsurpassed functionality in control, user interface and handling

Our rotary indexing machines with high numbers of axes place exceptional demands on the functionality of the control system, the user interface and data handling. Transferring our many years of experience to a new control concept and realizing further improvements with this step is an enormous challenge. But early in the development phase, multiple laboratory tests at Rexroth contributed greatly to our progress. By means of simulations, we were able to decisively enhance the control technology basis of the mechanical components with regard to the desired quality of control. Not only were all requirements of the specification met, but the extremely constructive and creative collaboration generated additional ideas for further optimizing operating convenience and ease of retooling before the start of series production.

The Rexroth HNC100®-3X motion control-system assumes the micrometer-precise control of the hydraulic feed axes. Its software takes into account all special characteristics of the fluid technology, thus decoupling the drive from the control level. IndraWorks provides the same software tools for the electrical commissioning of the hydraulic axes as for the other drives, which greatly simplifies our work. And particularly decisive: the IndraMotion MTX control unit with HNC/ IAC control technology is uniquely suited to our requirements. We know of no other system with comparable performance on the market.

Real-time communication cuts cycle time

All electrical and hydraulic drives communicate with the controller via sercos. The Ethernet-based automation bus uses strictly deterministic real-time mechanisms. By combining HNC with sercos and the IndraMotion MTX, we can increase output by 20 percent compared to solutions previously available and we can even machine two workpieces simultaneously with no difficulties. The controller concurrently coordinates multiple working steps. Predefined functions simplified engineering. It is of course an advantage that the entire automation was supplied by a single source; that simplifies interface matching enormously. Rexroth supported us intensively in all technologies throughout the entire development phase and thus cut our time to market significantly.

 

The Author

 
Photo | Winema Maschinenau

Eckhard Neth,

Geschäftsführer

Winema Maschinenbau GmbH

www.winema.de